Anti-Zika virus antibodies and methods of use

ABSTRACT

The present invention provides monoclonal antibodies, or antigen-binding fragments thereof, that bind to ZIKV glycoproteins, pharmaceutical compositions comprising the antibodies and methods of use. The antibodies of the invention are useful for inhibiting or neutralizing ZIKV activity, thus providing a means of treating or preventing ZIKV infection in humans. In some embodiments, the invention provides for use of one or more antibodies that bind to the ZIKV for preventing viral attachment and/or entry into host cells. The antibodies of the invention may be used prophylactically or therapeutically and may be used alone or in combination with one or more other anti-viral agents or vaccines.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C § 119(e) of U.S. provisional application Nos. 62/363,546, filed Jul. 18, 2016 and 62/474,753 filed Mar. 22, 2017, both of which are herein specifically incorporated by reference in their entireties.

REFERENCE TO A SEQUENCE LISTING

This application incorporates by reference the Sequence Listing submitted in Computer Readable Form as file 10278US01-Sequence.txt, created on Jul. 17, 2017 and containing 212,262 bytes.

FIELD OF THE INVENTION

The present invention relates to antibodies that bind to Zika virus envelope glycoprotein, pharmaceutical compositions comprising these antibodies and methods of use thereof.

BACKGROUND

Zika virus (ZIKV) is a positive-stranded RNA arthropod-borne virus (arbovirus) in the genus Flavivirus, family Flaviviridae (Gubler, D J, et al., In: Knipe, D M, et al., eds., Fields Virology, 5^(th) edn., Philadelphia, Pa.: Lippincott Williams & Wilkins Publishers, 2007:1155-227). It is thought to be principally transmitted to humans by the mosquito, Aedes aegypti. In addition to transmission by mosquitoes, ZIKV may be sexually (Foy, B D, et al., (2011), Emerg. Infect. Dis. 17:880-882) and vertically (Mlakar, J. et al., (2016), N. Engl. J. Med. 374:951-958) transmitted, or transmitted via blood products or tissue samples. ZIKV generally causes a mild disease, with a rash and mild febrile illness in the majority of symptomatic individuals. However, when pregnant women are infected with ZIKV, there is an increased risk of developing microcephaly in the fetus (Schuler-Faccini, L. et al., (2016), MMWR Morb. Mortal. Wkly Rep. 65:59-62) or other developmental abnormalities (Brasil et al., (2016) N. Engl. J. Med., March 4). There have also been reports that ZIKV is associated with Guillain-Barré syndrome in patients infected with the virus (Cao-Lormeau, V M, et al., (2016), Lancet, April 9:387(10027):1531-9). In addition, there have also been reports of an association of ZIKV with brain ischemia, myelitis and meningoencephalitis (Carteaux, G. et al. (2016), N. Engl. J. Med. 374(16):1595).

The tropism and pathogenesis of ZIKV are largely unknown. In general, flaviviruses are enveloped viruses containing a single strand RNA genome of about 11,000 bases complexed with multiple copies of the capsid protein, surrounded by an icosahedral shell consisting of 180 copies each of the envelope glycoprotein (E) (˜500 amino acids), and the membrane protein (M) (˜75 amino acids) or precursor membrane protein (prM) (˜165 amino acids), all anchored in a lipid membrane. The genome also codes for seven non-structural proteins that are involved in replication and assembly (Sirohi, D. et al., (2016), Science, 352:467-470).

During their life cycle, flavivirus virions exist in an immature (non-infectious) state and a mature (infectious) state (Lindenbach, BD, In: Fields Virology, Knipe, D M and Howley, PM, eds, Philadelphia, Pa.: Lippincott Williams & Wilkins Publishers, Ed. 6, Vol. 1, 2013, Chapter 25, pp. 712-746).

The ZIKV envelope glycoprotein (E) may be a target for protective antibodies, but to date, no antibodies specific for ZIKV envelope glycoprotein are in clinical testing. Accordingly, there is still a need in the art to identify new antibodies, which can be used to prevent or treat a ZIKV infection.

BRIEF SUMMARY OF THE INVENTION

The present invention provides antibodies and antigen-binding fragments thereof that bind ZIKV E. The antibodies of the present invention are useful for inhibiting or neutralizing the activity of ZIKV. In some embodiments, the antibodies are useful for blocking attachment of ZIKV to the host cell, or for preventing fusion of the virus to the host cell membrane. In so doing, the antibodies of the invention block entry of the virus into host cells. In certain embodiments, the antibodies are useful in preventing, treating or ameliorating at least one symptom of ZIKV infection in a subject. In certain embodiments, the antibodies of the invention may neutralize the virus and in so doing, may prevent transmission of the virus in a pregnant female to her fetus thus preventing microcephaly (or other developmental abnormalities) in the fetus of the pregnant female. In certain embodiments, the antibodies may be administered prophylactically or therapeutically to a subject having, or at risk of acquiring, or at risk of transmitting a ZIKV infection. In certain embodiments, compositions containing at least one antibody of the invention may be administered to a subject for whom a vaccine is contra-indicated, or for whom a vaccine is less efficacious, for example, an elderly patient, a very young patient, a pregnant female patient, a patient who may be allergic to any one or more components of a vaccine, or an immunocompromised patient who may be non-responsive to the immunogens in a vaccine. In certain embodiments, compositions containing at least one antibody of the invention may be administered to a pregnant female, medical staff, hospitalized patients or nursing home residents, an individual traveling to a country known to have a ZIKV outbreak, or traveling to a country know to have mosquitoes carrying the ZIKV, or other high-risk patients during a ZIKV outbreak. In certain embodiments, compositions containing at least one antibody of the invention may be administered as a first line treatment to patients who have already been exposed to ZIKV.

The antibodies of the invention can be full-length (for example, an IgG1 or IgG4 antibody) or may comprise only an antigen-binding portion (for example, a Fab, F(ab′)₂ or scFv fragment), and may be modified to affect functionality, e.g., to increase persistence in the host or to eliminate residual effector functions (Reddy et al., 2000, J. Immunol. 164:1925-1933). In certain embodiments, the antibodies may be bispecific.

In a first aspect, the present invention provides isolated recombinant monoclonal antibodies or antigen-binding fragments thereof that bind specifically to the ZIKV envelope glycoprotein (E).

In one embodiment, the present invention provides an isolated recombinant antibody or antigen-binding fragment thereof that specifically binds to ZIKV and/or a ZIKV E, wherein the antibody or antigen-binding fragment thereof neutralizes ZIKV in vitro with an IC₅₀ less than or equal to 10⁻⁹M and wherein the antibody or antigen-binding fragment thereof demonstrates a protective effect in vivo in a ZIKV infected animal.

In one embodiment, the present invention provides an isolated recombinant antibody or antigen-binding fragment thereof that specifically binds to ZIKV and/or a ZIKV E, wherein the antibody has one or more of the following characteristics:

(a) is a fully human monoclonal antibody;

(b) binds to a VLP expressing Zika prM/E with an EC₅₀ ranging from about 80 pM to about 150 nM;

(c) binds to ZIKV E with a dissociation constant (K_(D)) of less than 10⁻⁷M, as measured in a surface plasmon resonance assay; or

(d) may or may not demonstrate a change in dissociative half-life (t½) at pH 5 or pH 6 relative to pH 7.4.

Exemplary anti-ZIKV E antibodies of the present invention are listed in Tables 1 and 2 herein. Table 1 sets forth the amino acid sequence identifiers of the heavy chain variable regions (HCVRs), light chain variable regions (LCVRs), heavy chain complementarity determining regions (HCDR1, HCDR2 and HCDR3), and light chain complementarity determining regions (LCDR1, LCDR2 and LCDR3) of exemplary anti-ZIKV E antibodies. Table 2 sets forth the nucleic acid sequence identifiers of the HCVRs, LCVRs, HCDR1, HCDR2 HCDR3, LCDR1, LCDR2 and LCDR3 of the exemplary anti-ZIKV E antibodies.

The present invention provides antibodies, or antigen-binding fragments thereof, comprising an HCVR comprising an amino acid sequence selected from any of the HCVR amino acid sequences listed in Table 1, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

The present invention also provides antibodies, or antigen-binding fragments thereof, comprising an LCVR comprising an amino acid sequence selected from any of the LCVR amino acid sequences listed in Table 1, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

The present invention also provides antibodies, or antigen-binding fragments thereof, comprising an HCVR and an LCVR amino acid sequence pair (HCVR/LCVR) comprising any of the HCVR amino acid sequences listed in Table 1 paired with any of the LCVR amino acid sequences listed in Table 1. According to certain embodiments, the present invention provides antibodies, or antigen-binding fragments thereof, comprising an HCVR/LCVR amino acid sequence pair contained within any of the exemplary anti-ZIKV E antibodies listed in Table 1.

In one embodiment, the isolated anti-ZIKV monoclonal antibodies or antigen-binding fragments comprise the three heavy chain complementarity determining regions (HCDR1, HCDR2 and HCDR3) contained within any one of the heavy chain variable region (HCVR) sequences selected from the group consisting of SEQ ID NOs: 2, 18, 34, 50, 66, 82, 98, 114, 130, 146, 162, 178, 194, 210, 226, 242, 258, 274, 290, 306, 322 and 338; and the three light chain complementarity determining regions (LCDR1, LCDR2 and LCDR3) contained within any one of the light chain variable region (LCVR) sequences selected from the group consisting of SEQ ID NOs: 10, 26, 42, 58, 74, 90, 106, 122, 138, 154, 170, 186, 202, 218, 234, 250, 266, 282, 298, 314, 330 and 346.

In one embodiment, the isolated anti-ZIKV monoclonal antibodies or antigen-binding fragments thereof comprise a HCVR having an amino acid sequence selected from the group consisting of SEQ ID NOs: 2, 18, 34, 50, 66, 82, 98, 114, 130, 146, 162, 178, 194, 210, 226, 242, 258, 274, 290, 306, 322 and 338.

In one embodiment, the isolated anti-ZIKV monoclonal antibodies or antigen-binding fragments thereof comprise a LCVR having an amino acid sequence selected from the group consisting of SEQ ID NOs: 10, 26, 42, 58, 74, 90, 106, 122, 138, 154, 170, 186, 202, 218, 234, 250, 266, 282, 298, 314, 330 and 346.

In one embodiment, the isolated antibody or antigen-binding fragment comprises a HCVR/LCVR amino acid sequence pair selected from the group consisting of SEQ ID NOs: 2/10, 18/26, 34/42, 50/58, 66/74, 82/90, 98/106, 114/122, 130/138, 146/154, 162/170, 178/186, 194/202, 210/218, 226/234, 242/250, 258/266, 274/282, 290/298, 306/314, 322/330 and 338/346.

In certain embodiments, the HCVR/LCVR amino acid sequence pair is selected from the group consisting of SEQ ID NOs: 66/74 (H4H25598P), SEQ ID NOs: 114/122 (H4H25619P), and SEQ ID NOs: 258/266 (H4H25703N). In one embodiment, the HCVR/LCVR amino acid sequence pair is selected from the group consisting of SEQ ID NOs: 114/122 (H4H25619P) and SEQ ID NOs: 258/266 (H4H25703N).

In one embodiment, the isolated antibody or antigen-binding fragment comprises:

(a) a HCDR1 domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 4, 20, 36, 52, 68, 84, 100, 116, 132, 148, 164, 180, 196, 212, 228, 244, 260, 276, 292, 308, 324 and 340;

(b) a HCDR2 domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 6, 22, 38, 54, 70, 86, 102, 118, 134, 150, 166, 182, 198, 214, 230, 246, 262, 278, 294, 310, 326 and 342;

(c) a HCDR3 domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 8, 24, 40, 56, 72, 88, 104, 120, 136, 152, 168, 184, 200, 216, 232, 248, 264, 280, 296, 312, 328 and 344;

(d) a LCDR1 domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 12, 28, 44, 60, 76, 92, 108, 124, 140, 156, 172, 188, 204, 220, 236, 252, 268, 284, 300, 316, 332 and 348;

(e) a LCDR2 domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 14, 30, 46, 62, 78, 94, 110, 126, 142, 158, 174, 190, 206, 222, 238, 254, 270, 286, 302, 318, 334 and 350;

(f) a LCDR3 domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, 240, 256, 272, 288, 304, 320, 336 and 352.

In one embodiment, the isolated antibody or antigen-binding fragment thereof comprises an HCDR1 amino acid sequence of SEQ ID NO: 68; an HCDR2 amino acid sequence of SEQ ID NO: 70; an HCDR3 amino acid sequence of SEQ ID NO: 72; an LCDR1 amino acid sequence of SEQ ID NO: 76; an LCDR2 amino acid sequence of SEQ ID NO: 78 and an LCDR3 amino acid sequence of SEQ ID NO: 80.

In one embodiment, the isolated antibody or antigen-binding fragment thereof comprises an HCDR1 amino acid sequence of SEQ ID NO: 116; an HCDR2 amino acid sequence of SEQ ID NO: 118; an HCDR3 amino acid sequence of SEQ ID NO: 120; an LCDR1 amino acid sequence of SEQ ID NO: 124; an LCDR2 amino acid sequence of SEQ ID NO: 126 and an LCDR3 amino acid sequence of SEQ ID NO: 128.

In one embodiment, the isolated antibody or antigen-binding fragment thereof comprises an HCDR1 amino acid sequence of SEQ ID NO: 260; an HCDR2 amino acid sequence of SEQ ID NO: 262; an HCDR3 amino acid sequence of SEQ ID NO: 264; an LCDR1 amino acid sequence of SEQ ID NO: 268; an LCDR2 amino acid sequence of SEQ ID NO: 270 and an LCDR3 amino acid sequence of SEQ ID NO: 272.

The present invention also provides antibodies, or antigen-binding fragments thereof, comprising a heavy chain CDR1 (HCDR1) comprising an amino acid sequence selected from any of the HCDR1 amino acid sequences listed in Table 1 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

The present invention also provides antibodies, or antigen-binding fragments thereof, comprising a heavy chain CDR2 (HCDR2) comprising an amino acid sequence selected from any of the HCDR2 amino acid sequences listed in Table 1 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

The present invention also provides antibodies, or antigen-binding fragments thereof, comprising a heavy chain CDR3 (HCDR3) comprising an amino acid sequence selected from any of the HCDR3 amino acid sequences listed in Table 1 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

The present invention also provides antibodies, or antigen-binding fragments thereof, comprising a light chain CDR1 (LCDR1) comprising an amino acid sequence selected from any of the LCDR1 amino acid sequences listed in Table 1 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

The present invention also provides antibodies, or antigen-binding fragments thereof, comprising a light chain CDR2 (LCDR2) comprising an amino acid sequence selected from any of the LCDR2 amino acid sequences listed in Table 1 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

The present invention also provides antibodies, or antigen-binding fragments thereof, comprising a light chain CDR3 (LCDR3) comprising an amino acid sequence selected from any of the LCDR3 amino acid sequences listed in Table 1 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

The present invention also provides antibodies, or antigen-binding fragments thereof, comprising an HCDR3 and an LCDR3 amino acid sequence pair (HCDR3/LCDR3) comprising any of the HCDR3 amino acid sequences listed in Table 1 paired with any of the LCDR3 amino acid sequences listed in Table 1. According to certain embodiments, the present invention provides antibodies, or antigen-binding fragments thereof, comprising an HCDR3/LCDR3 amino acid sequence pair contained within any of the exemplary anti-ZIKV E antibodies listed in Table 1. In certain embodiments, the HCDR3/LCDR3 amino acid sequence pair is SEQ ID NOs: 72/80 (e.g., H4H25598P) and 264/272 (e.g., H4H25703N).

The present invention also provides antibodies, or antigen-binding fragments thereof, comprising a set of six CDRs HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3) contained within any of the exemplary anti-ZIKV E antibodies listed in Table 1. In certain embodiments, the HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 amino acid sequence set is selected from the group consisting of SEQ ID NOs: 68-70-72-76-78-80 (e.g., H4H25598P), SEQ ID NOs: 116, 118, 120, 124, 126 and 128 (H4H25619P), and SEQ ID NOs: 260-262-264-268-270-272 (e.g., H4H25703N).

In a related embodiment, the present invention provides antibodies, or antigen-binding fragments thereof, comprising a set of six CDRs HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3) contained within an HCVR/LCVR amino acid sequence pair as defined by any of the exemplary anti-ZIKV E antibodies listed in Table 1. For example, the present invention includes antibodies, or antigen-binding fragments thereof, comprising the HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 amino acid sequences set contained within an HCVR/LCVR amino acid sequence pair selected from the group consisting of SEQ ID NOs: 66/74 (e.g., H4H25598P), SEQ ID NO: 114/122 (e.g. H4H25619P) and 258/266 (e.g., H4H25703N). Methods and techniques for identifying CDRs within HCVR and LCVR amino acid sequences are well known in the art and can be used to identify CDRs within the specified HCVR and/or LCVR amino acid sequences disclosed herein. Exemplary conventions that can be used to identify the boundaries of CDRs include, e.g., the Kabat definition, the Chothia definition, and the AbM definition. In general terms, the Kabat definition is based on sequence variability, the Chothia definition is based on the location of the structural loop regions, and the AbM definition is a compromise between the Kabat and Chothia approaches. See, e.g., Kabat, “Sequences of Proteins of Immunological Interest,” National Institutes of Health, Bethesda, Md. (1991); Al-Lazikani et al., J. Mol. Biol. 273:927-948 (1997); and Martin et al., Proc. Natl. Acad. Sci. USA 86:9268-9272 (1989). Public databases are also available for identifying CDR sequences within an antibody.

In one embodiment, the invention provides an anti-ZIKV antibody that binds specifically to ZIKV and has a heavy chain (HC) amino acid sequence of SEQ ID NO: 367 and a light chain (LC) amino acid sequence of SEQ ID NO: 368.

In one embodiment, the invention provides an anti-ZIKV antibody that binds specifically to ZIKV and has a heavy chain (HC) amino acid sequence of SEQ ID NO: 370 and a light chain (LC) amino acid sequence of SEQ ID NO: 371.

In one embodiment, the invention provides an anti-ZIKV antibody that binds specifically to ZIKV and has a heavy chain (HC) amino acid sequence of SEQ ID NO: 373 and a light chain (LC) amino acid sequence of SEQ ID NO: 374.

In one embodiment, the invention provides an anti-ZIKV antibody that binds specifically to ZIKV and has a heavy chain (HC) amino acid sequence of SEQ ID NO: 369 and a light chain (LC) amino acid sequence of SEQ ID NO: 368.

In one embodiment, the invention provides an anti-ZIKV antibody that binds specifically to ZIKV and has a heavy chain (HC) amino acid sequence of SEQ ID NO: 372 and a light chain (LC) amino acid sequence of SEQ ID NO: 371.

In one embodiment, the invention provides an anti-ZIKV antibody that binds specifically to ZIKV and has a heavy chain (HC) amino acid sequence of SEQ ID NO: 375 and a light chain (LC) amino acid sequence of SEQ ID NO: 374.

In one embodiment, the antibodies of the invention are capable of neutralizing the ZIKV strains selected from the group consisting of MR766 (Uganda 1947), PRVABC59 (Puerto Rico 2015) and FLR (Colombia 2015) strains.

In one aspect of the invention, the invention provides a human antibody, an antibody variant, or an antigen binding fragment thereof that neutralizes ZIKV, wherein the antibody, antibody variant, or antigen binding fragment does not contribute to, cause, or induce, antibody-dependent enhancement (ADE). In one embodiment, the antibody or antigen-binding fragment thereof does not contribute to, cause, or induce, antibody-dependent enhancement (ADE) of a ZIKV infection, or infection with one or more other viruses in the Flavivirus family, e.g. Dengue virus.

In one embodiment, the invention provides an antibody that neutralizes a ZIKV having a wild type E protein (See e.g. SEQ ID NO: 376), but does not neutralize a ZIKV having a mutated form of the E protein, wherein the mutation is a serine to phenylalanine at position 302 of SEQ ID NO: 376 (S302F), a threonine to isoleucine at position 311 of SEQ ID NO: 376 (T311I), or a lysine to glutamic acid at position 369 of SEQ ID NO: 376 (K369E).

In one embodiment, the invention provides a human antibody, an antibody variant, or an antigen binding fragment thereof that neutralizes ZIKV, wherein the antibody, antibody variant, or antigen-binding fragment comprises one or more mutations in the Fc region, wherein the one or more mutations reduce binding of the antibody to an Fc receptor on a cell.

In one embodiment, the invention provides a human antibody, an antibody variant, or an antigen-binding fragment thereof that neutralizes ZIKV, wherein the antibody, antibody variant, or antigen-binding fragment comprises one or more mutations in the Fc region, wherein the one or more mutations result in a longer serum half life of the antibody. In one embodiment, the mutation consists of a YTE modification at positions 131, 133 and 135 of SEQ ID NO: 357 (M131Y, S133T and T135E). These changes are shown at these positions in SEQ ID NO: 358.

In one embodiment, the invention provides a human antibody, an antibody variant, or an antigen binding fragment thereof that neutralizes ZIKV, wherein the antibody, antibody variant, or antigen binding fragment comprises at least one mutation in the Fc region that results in reduced binding of the antibody to an Fc receptor on a cell and at least one mutation that results in an increase in the serum half life of the antibody.

The present invention includes anti-ZIKV antibodies comprising an Fc domain, wherein the Fc domain comprises IgG1 or IgG4 isotypes as described elsewhere herein.

In certain embodiments, an anti-ZIKV antibody of the invention comprises an Fc domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 356 (IgG1), 357 (IgG4 without a YTE mutation), 358 (IgG4 with a YTE mutation), 365 (IgG4 without a YTE mutation) and 366 (IgG4 with a YTE mutation).

In one embodiment, an anti-ZIKV antibody of the invention comprises an Fc domain having the amino acid sequence of SEQ ID NO: 357.

In one embodiment, an anti-ZIKV antibody of the invention comprises an Fc domain having the amino acid sequence of SEQ ID NO: 358.

In one embodiment, an anti-ZIKV antibody of the invention comprises an HCVR/LVCR amino acid sequence pair of SEQ ID NOs: 258/266 and an Fc domain having the amino acid sequence of SEQ ID NO: 357 or 358.

In one embodiment, an anti-ZIKV antibody of the invention comprises an HCVR/LVCR amino acid sequence pair of SEQ ID NOs: 114/122 and an Fc domain having the amino acid sequence of SEQ ID NO: 357 or 358.

In one embodiment, an anti-ZIKV antibody of the invention comprises an HCVR/LVCR amino acid sequence pair of SEQ ID NOs: 114/122 and an Fc domain having the amino acid sequence of SEQ ID NO: 357.

In one embodiment, an anti-ZIKV antibody of the invention comprises an HCVR/LVCR amino acid sequence pair of SEQ ID NOs: 66/74 and an Fc domain having the amino acid sequence of SEQ ID NO: 357 or 358.

In one embodiment, an anti-ZIKV antibody of the invention comprises an HCVR/LVCR amino acid sequence pair of SEQ ID NOs: 66/74 and an Fc domain having the amino acid sequence of SEQ ID NO: 357.

The present invention includes anti-ZIKV antibodies having a modified glycosylation pattern. In some embodiments, modification to remove undesirable glycosylation sites may be useful, or an antibody lacking a fucose moiety present on the oligosaccharide chain, for example, to increase antibody dependent cellular cytotoxicity (ADCC) function (see Shield et al. (2002) JBC 277:26733). In other applications, modification of galactosylation can be made in order to modify complement dependent cytotoxicity (CDC).

The present invention also provides antibodies and antigen-binding fragments thereof that cross-compete for binding to ZIKV, or that bind the same epitope as a reference antibody or antigen-binding fragment thereof comprising the CDRs of a HCVR and the CDRs of a LCVR, wherein the HCVR and LCVR each has an amino acid sequence selected from the HCVR and LCVR sequences listed in Table 1.

The present invention also provides isolated antibodies and antigen-binding fragments thereof that block ZIKV attachment to a cell, or prevent fusion of the virus to a cell membrane, thereby preventing entry of the virus into a host cell.

In certain embodiments, the antibodies or antigen-binding fragments of the present invention are bispecific comprising a first binding specificity to a first epitope in the ZIKV and a second binding specificity to a second epitope in the ZIKV, wherein the first and second epitopes are distinct and non-overlapping. In certain embodiments the bispecific may comprise a first arm that binds to an epitope in the viral envelope glycoprotein and a second arm that binds to an epitope in a different viral antigen.

In a second aspect, the present invention provides nucleic acid molecules encoding anti-ZIKV antibodies or portions thereof. For example, the present invention provides nucleic acid molecules encoding any of the HCVR amino acid sequences listed in Table 1; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the HCVR nucleic acid sequences listed in Table 2, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

The present invention also provides nucleic acid molecules encoding any of the LCVR amino acid sequences listed in Table 1; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the LCVR nucleic acid sequences listed in Table 2, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

The present invention also provides nucleic acid molecules encoding any of the HCDR1 amino acid sequences listed in Table 1; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the HCDR1 nucleic acid sequences listed in Table 2, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

The present invention also provides nucleic acid molecules encoding any of the HCDR2 amino acid sequences listed in Table 1; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the HCDR2 nucleic acid sequences listed in Table 2, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

The present invention also provides nucleic acid molecules encoding any of the HCDR3 amino acid sequences listed in Table 1; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the HCDR3 nucleic acid sequences listed in Table 2, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

The present invention also provides nucleic acid molecules encoding any of the LCDR1 amino acid sequences listed in Table 1; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the LCDR1 nucleic acid sequences listed in Table 2, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

The present invention also provides nucleic acid molecules encoding any of the LCDR2 amino acid sequences listed in Table 1; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the LCDR2 nucleic acid sequences listed in Table 2, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

The present invention also provides nucleic acid molecules encoding any of the LCDR3 amino acid sequences listed in Table 1; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the LCDR3 nucleic acid sequences listed in Table 2, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

The present invention also provides nucleic acid molecules encoding an HCVR, wherein the HCVR comprises a set of three CDRs (i.e., HCDR1-HCDR2-HCDR3), wherein the HCDR1-HCDR2-HCDR3 amino acid sequence set is as defined by any of the exemplary anti-ZIKV E antibodies listed in Table 1.

The present invention also provides nucleic acid molecules encoding an LCVR, wherein the LCVR comprises a set of three CDRs (i.e., LCDR1-LCDR2-LCDR3), wherein the LCDR1-LCDR2-LCDR3 amino acid sequence set is as defined by any of the exemplary anti-ZIKV E antibodies listed in Table 1.

The present invention also provides nucleic acid molecules encoding both an HCVR and an LCVR, wherein the HCVR comprises an amino acid sequence of any of the HCVR amino acid sequences listed in Table 1, and wherein the LCVR comprises an amino acid sequence of any of the LCVR amino acid sequences listed in Table 1. In certain embodiments, the nucleic acid molecule comprises a polynucleotide sequence selected from any of the HCVR nucleic acid sequences listed in Table 2, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto, and a polynucleotide sequence selected from any of the LCVR nucleic acid sequences listed in Table 2, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto. In certain embodiments according to this aspect of the invention, the nucleic acid molecule encodes an HCVR and LCVR, wherein the HCVR and LCVR are both derived from the same anti-ZIKV E antibody listed in Table 1.

The present invention provides nucleic acid molecules encoding any of the heavy chain amino acid sequences listed in Table 1. The present invention also provides nucleic acid molecules encoding any of the light chain amino acid sequences listed in Table 1.

In a related aspect, the present invention provides recombinant expression vectors capable of expressing a polypeptide comprising a heavy or light chain variable region of an anti-ZIKV E antibody. For example, the present invention includes recombinant expression vectors comprising any of the nucleic acid molecules mentioned above, i.e., nucleic acid molecules encoding any of the HCVR, LCVR, and/or CDR sequences as set forth in Table 1. Also included within the scope of the present invention are host cells into which such vectors have been introduced, as well as methods of producing the antibodies or portions thereof by culturing the host cells under conditions permitting production of the antibodies or antibody fragments, and recovering the antibodies and antibody fragments so produced.

In a third aspect, the invention provides a pharmaceutical composition comprising one or more isolated monoclonal antibodies or antigen-binding fragments thereof which specifically bind to ZIKV E and a pharmaceutically acceptable carrier or diluent. The one or more isolated antibodies comprise an HCVR/LCVR amino acid sequence pair selected from the group consisting of the HCVR and LCVR sequences listed in Table 1. In one embodiment, the one or more isolated monoclonal antibodies tor antigen-binding fragments thereof that bind specifically to ZIKV comprise the three heavy chain complementarity determining regions (HCDR1, HCDR2 and HCDR3) contained within any one of the heavy chain variable region (HCVR) sequences selected from the group consisting of SEQ ID NOs: 2, 18, 34, 50, 66, 82, 98, 114, 130, 146, 162, 178, 194, 210, 226, 242, 258, 274, 290, 306, 322 and 338; and the three light chain complementarity determining regions (LCDR1, LCDR2 and LCDR3) contained within any one of the light chain variable region (LCVR) sequences selected from the group consisting of SEQ ID NOs: 10, 26, 42, 58, 74, 90, 106, 122, 138, 154, 170, 186, 202, 218, 234, 250, 266, 282, 298, 314, 330 and 346. In one embodiment, the HCVR/LCVR amino acid sequence pair is selected from the group consisting of SEQ ID NOs: 2/10, 18/26, 34/42, 50/58, 66/74, 82/90, 98/106, 114/122, 130/138, 146/154, 162/170, 178/186, 194/202, 210/218, 226/234, 242/250, 258/266, 274/282, 290/298, 306/314, 322/330 and 338/346. In one embodiment, the HCVR/LCVR amino acid sequence pair is selected from the group consisting of SEQ ID NOs: 66/74, 114/122 and 258/266. In one embodiment, the HCVR/LCVR amino acid sequence pair is selected from the group consisting of SEQ ID NOs: 114/122 and 258/266.

In one embodiment, the pharmaceutical composition comprises:

a) an isolated first monoclonal antibody, or antigen-binding fragment thereof that binds specifically to ZIKV, comprising a HCDR1 having the amino acid sequence of SEQ ID NO: 116, a HCDR2 having the amino acid sequence of SEQ ID NO: 118, a HCDR3 having the amino acid sequence of SEQ ID NO: 120, a LCDR1 having the amino acid sequence of SEQ ID NO: 124, a LCDR2 having the amino acid sequence of SEQ ID NO: 126, a LCDR3 having the amino acid sequence of SEQ ID NO: 128;

b) an isolated second monoclonal antibody, or antigen-binding fragment thereof that binds specifically to ZIKV, comprising a HCDR1 having the amino acid sequence of SEQ ID NO: 260, a HCDR2 having the amino acid sequence of SEQ ID NO: 262, a HCDR3 having the amino acid sequence of SEQ ID NO: 264, a LCDR1 having the amino acid sequence of SEQ ID NO: 268, a LCDR2 having the amino acid sequence of SEQ ID NO: 270, a LCDR3 having the amino acid sequence of SEQ ID NO: 272; and

c) a pharmaceutically acceptable carrier or diluent.

In a related aspect, the invention features a pharmaceutical composition comprising at least two antibodies of the invention and a pharmaceutically acceptable carrier or diluent.

In one embodiment, the pharmaceutical composition comprises at least two isolated monoclonal antibodies or antigen-binding fragments thereof that bind specifically to ZIKV, and a pharmaceutically acceptable carrier or diluent, wherein at least one of the two monoclonal antibodies neutralizes ZIKV in vitro with an IC₅₀ equal to or less than about 10⁻⁹M and demonstrates a protective effect in vivo in a ZIKV infected animal.

In one embodiment, the at least two isolated antibodies are selected from a first and a second anti-ZIKV monoclonal antibody or antigen-binding fragment comprising the three heavy chain complementarity determining regions (HCDR1, HCDR2 and HCDR3) contained within any one of the heavy chain variable region (HCVR) sequences selected from the group consisting of SEQ ID NOs: 2, 18, 34, 50, 66, 82, 98, 114, 130, 146, 162, 178, 194, 210, 226, 242, 258, 274, 290, 306, 322 and 338; and the three light chain complementarity determining regions (LCDR1, LCDR2 and LCDR3) contained within any one of the light chain variable region (LCVR) sequences selected from the group consisting of SEQ ID NOs: 10, 26, 42, 58, 74, 90, 106, 122, 138, 154, 170, 186, 202, 218, 234, 250, 266, 282, 298, 314, 330 and 346.

In one embodiment, the at least two isolated antibodies are selected from a first and a second anti-ZIKV monoclonal antibody or antigen-binding fragment thereof, wherein the first anti-ZIKV monoclonal antibody or antigen-binding fragment thereof comprises a HCDR1 having the amino acid sequence of SEQ ID NO: 116, a HCDR2 having the amino acid sequence of SEQ ID NO: 118, a HCDR3 having the amino acid sequence of SEQ ID NO: 120, a LCDR1 having the amino acid sequence of SEQ ID NO: 124, a LCDR2 having the amino acid sequence of SEQ ID NO: 126, and a LCDR3 having the amino acid sequence of SEQ ID NO: 128; and wherein the second anti-ZIKV monoclonal antibody, or antigen-binding fragment thereof that binds specifically to ZIKV, comprises a HCDR1 having the amino acid sequence of SEQ ID NO: 260, a HCDR2 having the amino acid sequence of SEQ ID NO: 262, a HCDR3 having the amino acid sequence of SEQ ID NO: 264, a LCDR1 having the amino acid sequence of SEQ ID NO: 268, a LCDR2 having the amino acid sequence of SEQ ID NO: 270, and a LCDR3 having the amino acid sequence of SEQ ID NO: 272.

In a related aspect, the invention features a composition comprising at least three antibodies of the invention and a pharmaceutically acceptable carrier or diluent.

In certain embodiments, the invention provides a pharmaceutical composition comprising: (a) a first anti-ZIKV antibody comprising an HCVR/LCVR amino acid sequence pair as described in Table 1, or antigen-binding fragment thereof; (b) a second anti-ZIKV antibody comprising an HCVR/LCVR amino acid sequence pair as described in Table 1, or antigen-binding fragment thereof, wherein the first antibody binds to a first epitope on ZIKV E and the second antibody binds to a second different epitope on ZIKV E wherein the first and second epitopes are distinct and non-overlapping; and (c) a pharmaceutically acceptable carrier or diluent.

In another related aspect, the invention features a composition, which comprises a combination of an anti-ZIKV E antibody and a second therapeutic agent.

In one embodiment, the second therapeutic agent is any agent that is advantageously combined with an anti-ZIKV E antibody. Exemplary agents that may be advantageously combined with an anti-ZIKV antibody include, without limitation, other agents that bind and/or inhibit ZIKV activity (including other antibodies or antigen-binding fragments thereof, etc.) and/or agents, which do not directly bind ZIKV but nonetheless inhibit viral activity (including infectivity of host cells) and/or viral pathogenesis.

In certain embodiments, the invention provides a pharmaceutical composition comprising: (a) a first anti-ZIKV antibody or antigen-binding fragment thereof; (b) a second anti-ZIKV antibody or antigen-binding fragment thereof, wherein the first antibody does not cross-compete with the second antibody for binding to ZIKV; and (c) a pharmaceutically acceptable carrier or diluent.

In certain embodiments, the invention provides a pharmaceutical composition comprising: (a) a first anti-ZIKV antibody or antigen-binding fragment thereof; (b) a second anti-ZIKV antibody or antigen-binding fragment thereof, which interacts with a different ZIKV antigen, wherein the first antibody binds to an epitope on ZIKV E and the second antibody binds to an epitope on a different ZIKV antigen; and (c) a pharmaceutically acceptable carrier or diluent.

In certain embodiments, the invention provides a pharmaceutical composition comprising: (a) a first anti-ZIKV antibody or antigen-binding fragment thereof; (b) a second anti-ZIKV antibody or antigen-binding fragment thereof; (c) a third anti-ZIKV antibody or antigen-binding fragment thereof, wherein the first antibody binds to a first epitope on ZIKV E and the second and/or third antibody binds to a different epitope on ZIKV E wherein the first, second and third epitopes are distinct and non-overlapping; and (d) a pharmaceutically acceptable carrier or diluent.

In certain embodiments, the invention provides a pharmaceutical composition comprising: (a) a first anti-ZIKV antibody or antigen-binding fragment thereof; (b) a second anti-ZIKV antibody or antigen-binding fragment thereof; (c) a third anti-ZIKV antibody or an antigen-binding fragment thereof, wherein the first antibody may or may not cross-compete with the second, and/or third antibody for binding to ZIKV; and (d) a pharmaceutically acceptable carrier or diluent.

In certain embodiments, the invention provides a pharmaceutical composition comprising: (a) a first anti-ZIKV antibody or antigen-binding fragment thereof; (b) a second and/or third anti-ZIKV antibody or antigen-binding fragment thereof, which interacts with a different ZIKV antigen, wherein the first antibody binds to an epitope on ZIKV E and the second and/or third antibody binds to an epitope on a different ZIKV antigen; and (c) a pharmaceutically acceptable carrier or diluent.

In one embodiment, the pharmaceutical composition comprises a first anti-ZIKV antibody or an antigen-binding fragment thereof that binds to, or interacts with one epitope on one strain of ZIKV and the second and/or third anti-ZIKV antibody or an antigen-binding fragment thereof that binds to, or interacts with a second and/or a third epitope on the same strain or on a different strain of ZIKV.

In a related aspect, the invention provides a pharmaceutical composition comprising a first isolated monoclonal antibody or an antigen-binding fragment thereof that binds specifically to ZIKV E, wherein the first isolated monoclonal antibody or an antigen-binding fragment thereof comprises an HCDR1 amino acid sequence of SEQ ID NO: 68; an HCDR2 amino acid sequence of SEQ ID NO: 70; an HCDR3 amino acid sequence of SEQ ID NO: 72; an LCDR1 amino acid sequence of SEQ ID NO: 76; an LCDR2 amino acid sequence of SEQ ID NO: 78 and an LCDR3 amino acid sequence of SEQ ID NO: 80, and a pharmaceutically acceptable carrier or diluent. The pharmaceutical composition may further comprise a second isolated monoclonal antibody or an antigen-binding fragment thereof that binds specifically to ZIKV E, wherein the second isolated monoclonal antibody or an antigen-binding fragment thereof comprises an HCDR1 amino acid sequence of SEQ ID NO: 116, or 260; an HCDR2 amino acid sequence of SEQ ID NO: 118, or 262; an HCDR3 amino acid sequence of SEQ ID NO: 120, or 264; an LCDR1 amino acid sequence of SEQ ID NO: 124, or 268; an LCDR2 amino acid sequence of SEQ ID NO: 126, or 270 and an LCDR3 amino acid sequence of SEQ ID NO: 128, or 272.

In one embodiment, the pharmaceutical composition comprises a first isolated monoclonal antibody or an antigen-binding fragment thereof that binds specifically to ZIKV wherein the first isolated monoclonal antibody or an antigen-binding fragment thereof comprises an HCDR1 amino acid sequence of SEQ ID NO: 116; an HCDR2 amino acid sequence of SEQ ID NO: 118; an HCDR3 amino acid sequence of SEQ ID NO: 120; an LCDR1 amino acid sequence of SEQ ID NO: 124; an LCDR2 amino acid sequence of SEQ ID NO: 126 and an LCDR3 amino acid sequence of SEQ ID NO: 128, and a pharmaceutically acceptable carrier or diluent. The pharmaceutical composition may further comprise a second isolated monoclonal antibody or an antigen-binding fragment thereof that binds specifically to ZIKV, wherein the second isolated monoclonal antibody or an antigen-binding fragment thereof comprises an HCDR1 amino acid sequence of SEQ ID NO: 260; an HCDR2 amino acid sequence of SEQ ID NO: 262; an HCDR3 amino acid sequence of SEQ ID NO: 264; an LCDR1 amino acid sequence of SEQ ID NO: 268; an LCDR2 amino acid sequence of SEQ ID NO: 270 and an LCDR3 amino acid sequence of SEQ ID NO: 272. The pharmaceutical composition may further comprise a third isolated monoclonal antibody or an antigen-binding fragment thereof that binds specifically to ZIKV E, wherein the third isolated monoclonal antibody or an antigen-binding fragment thereof comprises an HCDR1 amino acid sequence, an HCDR2 amino acid sequence; an HCDR3 amino acid sequence; an LCDR1 amino acid sequence; an LCDR2 amino acid sequence and an LCDR3 amino acid sequence from any of the antibodies shown in Table 1.

In a related aspect, the invention provides an antibody cocktail comprising a mixture of at least two antibodies that bind specifically to ZIKV, wherein the antibodies comprise the HCVR/LCVR amino acid sequence pairs selected from the group consisting of SEQ ID NOs: 2/10, 18/26, 34/42, 50/58, 66/74, 82/90, 98/106, 114/122, 130/138, 146/154, 162/170, 178/186, 194/202, 210/218, 226/234, 242/250, 258/266, 274/282, 290/298, 306/314, 322/330 and 338/346.

In one embodiment, the cocktail comprises a mixture of two antibodies comprising the HCVR/LCVR amino acid sequence pairs of SEQ ID NO: 114/122 and 258/266. In one embodiment, the antibody cocktail may comprise a third antibody comprising an amino acid sequence pair selected from an antibody shown in Table 1. In one embodiment, the third antibody comprises the HCVR/LCVR amino acid sequence pair of SEQ ID NO: 66/74.

In one embodiment, the antibody cocktail comprises a mixture of two antibodies comprising the heavy chain (HC)/light chain (LC) amino acid sequence pairs of SEQ ID NO: 367/368 and 370/371. In one embodiment, the antibody cocktail may comprise a third antibody comprising a HC/LC amino acid sequence pair of SEQ ID NOs: 373/374.

In certain embodiments, each antibody may be formulated as a separate formulation and if it is determined that more than one antibody is needed to achieve maximal therapeutic efficacy, each of the antibody formulations may be co-administered (concurrently, or sequentially), as needed. Alternatively, the antibody cocktail may be co-formulated.

In certain embodiments, when two or more antibodies are combined together in one pharmaceutical composition, they may or may not bind the same or overlapping epitopes on the ZIKV protein. Additional combination therapies and co-formulations involving the anti-ZIKV antibodies of the present invention are disclosed elsewhere herein.

In certain embodiments, the invention provides a pharmaceutical composition comprising two or more human antibodies, or antigen binding fragments thereof that bind ZIKV E, wherein at least one antibody may prevent attachment of the virus to the cell, and the second antibody may prevent fusion of the virus to the host cell membrane and as such, the composition may provide for prevention of viral entry into the cell and replication within the cell. In a related embodiment, the composition comprising two anti-zika antibodies may provide for prevention of ZIKV entry into the host cell, wherein the antibodies do not contribute to antibody-dependent enhancement (ADE) of ZIKV infection.

In certain embodiments, the anti-ZIKV antibodies of the invention that neutralize Zika virus without contributing to ADE comprise the HCVR/LCVR amino acid sequence pairs selected from the group consisting of SEQ ID NOs: 258/266, 114/122 and 66/74, each having an Fc amino acid sequence as shown in SEQ ID NO: 357.

In certain embodiments, the anti-ZIKV antibodies of the invention that neutralize Zika virus without contributing to ADE comprise the HC/LC amino acid sequence pairs of SEQ ID NOs: 367/368 (H4H25703N) and SEQ ID NOs: 370/371 (H4H25619P).

In certain embodiments, the anti-ZIKV antibodies of the invention that neutralize Zika virus without contributing to ADE and which may have an extended serum half life comprise the HCVR/LCVR amino acid sequence pairs selected from the group consisting of SEQ ID NOs: 258/266, 114/122 and 66/74, each having an Fc amino acid sequence as shown in SEQ ID NO: 358 (IgG4 with YTE mutation described elsewhere herein).

In certain embodiments, the anti-ZIKV antibodies of the invention that neutralize Zika virus without contributing to ADE and which may have an extended serum half life comprise the HC/LC amino acid sequence pairs of SEQ ID NOs: 369/368 (H4H25703N with a YTE mutation described elsewhere herein), SEQ ID NOs: 372/371 (H4H25619P with a YTE mutation described elsewhere herein) and SEQ ID NOs: 375/373 (H4H25598P with a YTE mutation described elsewhere herein).

In a fourth aspect, the invention provides therapeutic methods for treating a disease or disorder associated with ZIKV (such as a viral infection in a subject), or at least one symptom associated with the viral infection, or the frequency or severity of at least one symptom associated with ZIKV infection, using an anti-ZIKV E antibody or antigen-binding portion of an antibody of the invention, or a cocktail of at least two or more antibodies of the invention, wherein the therapeutic methods comprise administering a therapeutically effective amount of one or more antibodies or antigen-binding fragments of the invention to the subject in need thereof. In one embodiment, the methods comprise administering a combination (cocktail) of at least two, or at least three antibodies of the invention. In one embodiment, the antibody cocktail comprises two anti-ZIKV E antibodies having the amino acid sequence pairs as set forth in SEQ ID NOs: 114/122 and 258/266. The disorder treated is any disease or condition, which is improved, ameliorated, inhibited or prevented by inhibition of ZIKV activity. In certain embodiments, the invention provides methods to prevent, treat or ameliorate at least one symptom of ZIKV infection, the method comprising administering a therapeutically effective amount of at least one or more anti-ZIKV E antibodies or antigen-binding fragments thereof of the invention to a subject in need thereof.

In a related aspect, the invention provides a method of neutralizing infectious ZIKV, the method comprising exposing a cell infected with ZIKV to a composition comprising one or more anti-ZIKV antibodies or antigen-binding fragments thereof, wherein the exposing results in enhanced protection of the cell from virus infection, or from cell death. In certain embodiments, the exposing may be in vitro or in vivo. In one embodiment, the one or more anti-ZIKV antibodies or antigen-binding fragments thereof neutralize infectious ZIKV having a wild type E protein, wherein the wild type E protein has a serine at position 302 of SEQ ID NO: 376, a threonine at position 311 of SEQ ID NO: 376, and a lysine at position 369 of SEQ ID NO: 376, but will not neutralize an infectious ZIKV having a mutated form of the E protein, wherein the mutated form of the E protein contains one or more of the following changes: a phenylalanine at position 302 of SEQ ID NO: 376, an isoleucine at position 311 of SEQ ID NO: 376, or a glutamic acid at position 369 of SEQ ID NO: 376. In one embodiment, the methods comprise administering one or more antibodies of the invention. In one embodiment, the methods comprise administering a combination (cocktail) of at least two antibodies of the invention. In one embodiment, the antibody cocktail comprises two anti-ZIKV antibodies having the amino acid sequence pairs as set forth in SEQ ID NOs: 114/122 and 258/266.

In some embodiments, the present invention provides methods to ameliorate or reduce the severity, duration, or frequency of occurrence, of at least one symptom of ZIKV infection in a subject by administering one or more anti-ZIKV E antibodies of the invention, wherein the at least one symptom is selected from the group consisting of fever, headache, arthralgia, myalgia and a maculopapular rash.

In certain embodiments, the invention provides methods to decrease viral load in a subject, the methods comprising administering to the subject an effective amount of one or more antibodies or fragments thereof of the invention that binds ZIKV E and blocks attachment to, or fusion with the cell membrane and/or entry into the host cell, decreasing the likelihood of dissemination into the male reproductive organs.

In one embodiment, the invention provides for reducing the likelihood of transmission of ZIKV from an infected individual to another individual. In one embodiment, transmission of the virus to the fetus from an infected mother may be prevented using at least one antibody of the invention. In a related embodiment, transmission of ZIKV to the fetus from an infected mother may be prevented using at least two antibodies of the invention. In so doing, the treatment of the pregnant female with one or more of the antibodies of the invention may prevent the development of microcephaly (or developmental abnormalities) in the infant.

In a certain embodiment, transmission of ZIKV to a sexual partner may be prevented using at least one antibody of the invention. In a related embodiment, transmission of ZIKV to a sexual partner may be prevented using at least two antibodies of the invention.

In one embodiment, the subject in need thereof is a subject at risk for exposure to, or for acquiring a ZIKV infection, wherein the subject is selected from the group consisting of an a pregnant woman who has been exposed to ZIKV, or who has been bitten by a mosquito suspected of harboring ZIKV, a woman who is living in, or visiting an area where there is a ZIKV outbreak and who is considering conceiving a child, or an immunocompromised individual, a healthcare worker, a person who is suspected of having been exposed to a person harboring the ZIKV, a person who comes into physical contact or close physical proximity with an infected individual, a hospital employee, a pharmaceutical researcher, maintenance personnel responsible for cleaning a hospital facility or institution where a ZIKV patient has been treated, individuals who have visited, or are planning to visit an area or country known to have, or suspected of having an outbreak of ZIKV, or a country that is known to have mosquitoes that may harbor the virus.

In one embodiment, the subject in need thereof may be administered at least one anti-ZIKV antibody of the invention or an antigen-binding fragment thereof, or a pharmaceutical composition comprising at least one antibody or antigen-binding fragment thereof of the invention in combination with a second therapeutic agent. The second therapeutic agent may be selected from the group consisting of an anti-viral drug, an anti-inflammatory drug (such as corticosteroids, and non-steroidal anti-inflammatory drugs, such as antibodies to TNF, a different antibody to ZIKV, a vaccine for ZIKV and/or interferons (alpha/beta/or lambda).

In one embodiment, the pharmaceutical composition may be administered subcutaneously, intravenously, intradermally, intramuscularly, intranasally, or orally.

In a related embodiment, enhanced protection may be observed in a mammal exposed to, or infected with ZIKV when the mammal is treated with a pharmaceutical composition comprising one or more anti-ZIKV antibodies of the invention, or with an antibody cocktail, which comprises at least two or more antibodies of the invention.

In one embodiment, the enhanced protection observed may be measured by a decrease in the severity or frequency of at least one symptom associated with ZIKV infection, or by a decrease in viral load. The at least one symptom may be selected from the group consisting of fever, headache, arthralgia, myalgia and a maculopapular rash.

In one embodiment, enhanced protection is observed in a ZIKV infected mammal treated with one or more antibodies of the invention when there is no substantial loss in weight after viral infection.

In one embodiment, enhanced protection is observed in a ZIKV infected mammal treated with one or more antibodies of the invention, as measured by an increase in survival of the ZIKV infected mammal treated with one or more anti-ZIKV antibodies as compared to a ZIKV virus infected mammal who has not been treated with one or more antibodies of the invention.

The enhanced protection may be observed when one or more of the antibodies is used alone, or when one or more of the antibodies is used in combination with one or more additional therapeutic agents or anti-ZIKV treatment modalities.

The one or more additional therapeutic agents may be selected from the group consisting of an anti-viral drug, an anti-inflammatory drug (such as corticosteroids, and non-steroidal anti-inflammatory drugs, such as an antibody to TNF), a different antibody to ZIKV, a vaccine for ZIKV and/or interferons (alpha/beta/or lambda).

In one embodiment, the one or more additional therapeutic agents comprise one or more anti-ZIKV antibodies.

In one embodiment, the one or more anti-ZIKV antibodies comprise a heavy chain variable region (HCVR) and a light chain variable region (LCVR) amino acid sequence selected from the group consisting of any of the HCVR and LCVR amino acid sequences of Table 1.

In a related embodiment, the one or more anti-ZIKV antibodies comprise a heavy chain variable region (HCVR) and a light chain variable region (LCVR) amino acid sequence pair selected from the group consisting of SEQ ID NOs: 2/10, 18/26, 34/42, 50/58, 66/74, 82/90, 98/106, 114/122, 130/138, 146/154, 162/170, 178/186, 194/202, 210/218, 226/234, 242/250, 258/266, 274/282, 290/298, 306/314, 322/330 and 338/346.

In another related embodiment, the one or more anti-ZIKV antibodies comprise a heavy chain variable region (HCVR) and a light chain variable region (LCVR) amino acid sequence pair selected from the group consisting of SEQ ID NOs: 66/74 and 258/266.

In certain embodiments, the one or more antibodies or antigen-binding fragments thereof may be administered prophylactically or therapeutically to a subject having, or at risk of having, or pre-disposed to developing an ZIKV infection. The subjects at risk include, but are not limited to, a pregnant female who has been exposed to ZIKV, or who has been bitten by a mosquito suspected of harboring the ZIKV, a woman who is living in, or visiting an area where there is a ZIKV outbreak and who is considering conceiving a child, an immunocompromised person, for example, a person who is immunocompromised because of autoimmune disease, or those persons receiving immunosuppressive therapy (for example, following organ transplant), a person who receives a transplant or a blood sample from a person infected with ZIKV, or those persons afflicted with human immunodeficiency syndrome (HIV) or acquired immune deficiency syndrome (AIDS), certain forms of anemia that deplete or destroy white blood cells, those persons receiving radiation or chemotherapy, or those persons afflicted with an inflammatory disorder. Other subjects at risk for acquiring a ZIKV infection include healthcare workers, or any person who comes into physical contact or close physical proximity with an infected individual, or is exposed to bodily fluids or tissues from infected individuals, also has an increased risk of developing a ZIKV infection. Moreover, a subject is at risk of contracting a ZIKV infection due to proximity to an outbreak of the disease, e.g. a subject resides in a densely-populated city or in close proximity to subjects having confirmed or suspected ZIKV infections, or choice of employment, e.g. maintenance personnel responsible for cleaning a hospital facility or institution where a zika patient has been treated, a hospital employee, a pharmaceutical researcher, an individual who has visited or who is planning to visit an area or country known to have or suspected to have an outbreak of ZIKV, or known to have mosquitoes that may harbor the ZIKV.

In certain embodiments, the antibody or antigen-binding fragment thereof of the invention is administered in combination with a second therapeutic agent to the subject in need thereof. The second therapeutic agent may be selected from the group consisting of an anti-inflammatory drug (such as corticosteroids and non-steroidal anti-inflammatory drugs, for example, anti-TNF antibodies), an anti-infective drug, an anti-viral drug, a different antibody to ZIKV, a vaccine for ZIKV, or an interferon, a dietary supplement such as anti-oxidants and any other drug or therapy known in the art useful for ameliorating at least one symptom of the ZIKV infection, or for reducing the viral load in a patient. In certain embodiments, the second therapeutic agent may be an agent that helps to counteract or reduce any possible side effect(s) associated with an antibody or antigen-binding fragment thereof of the invention, if such side effect(s) should occur. The antibody or fragment thereof may be administered subcutaneously, intravenously, intradermally, intraperitoneally, orally, intranasally, intramuscularly, or intracranially. In one embodiment, the antibody may be administered as a single intravenous infusion for maximum concentration of the antibody in the serum of the subject. The antibody or fragment thereof may be administered at a dose of about 0.1 mg/kg of body weight to about 100 mg/kg of body weight of the subject. In certain embodiments, an antibody of the present invention may be administered at one or more doses comprising between 50 mg to 600 mg.

The present invention also includes an anti-ZIKV antibody or antigen-binding fragment thereof of the invention for use in treating a subject who has, or is suspected of having, or has been exposed to ZIKV, or for use in the manufacture of a medicament for the treatment of a disease or disorder that would benefit from the blockade of ZIKV attachment to a cell, or fusion with the cell membrane.

Other embodiments will become apparent from a review of the ensuing detailed description.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1. Shows the results of an immunofluorescence assay for measuring antibody dependent enhancement (ADE) using chimeric antibodies that cross-react with all Flaviviruses.

FIG. 2. Shows the protective effect of the anti-Zika antibody, H4H25703N, on prevention of weight loss in Zika virus infected mice.

FIG. 3. Shows the protective effect of the anti-Zika antibody, H4H25619P, on prevention of weight loss in Zika virus infected mice.

FIG. 4. Shows the protective effect of the anti-Zika antibody, H4H25703N, on survival in Zika virus infected mice.

FIG. 5. Shows the protective effect of the anti-Zika antibody, H4H25619P, on survival in Zika virus infected mice.

FIG. 6. Shows the results of an assay for measuring antibody dependent enhancement (ADE) using an anti-Zika virus antibody, H4H25703N, prepared as either an IgG1, or an IgG4.

FIG. 7. Shows the results of an assay for measuring antibody dependent enhancement (ADE) using an anti-Zika virus antibody, H4H25619P, prepared as either an IgG1, or an IgG4.

FIGS. 8A and 8B. Show ZIKV neutralization using escape mutants generated in the presence of antibodies H4H25703N and H4H25619P.

DETAILED DESCRIPTION

Before the present methods are described, it is to be understood that this invention is not limited to particular methods, and experimental conditions described, as such methods and conditions may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, preferred methods and materials are now described. All patents, applications and non-patent publications mentioned in this specification are incorporated herein by reference in their entireties.

Definitions

“Zika virus”, or “ZIKV” is a member of the Flaviviridae family, and has been associated with microcephaly and other developmental abnormalities in the fetuses of pregnant women exposed to the virus (Schuler-Faccini, L. et al., (2016), MMWR Morb. Mortal. Wkly Rep. 65:59-62) and has also been associated with Guillian-Barré syndrome in adults (Cao-Lormeau, V M, et al., (2016), Lancet, April 9; 387(10027):1531-9). The term “ZIKV” also includes variants of ZIKV isolated from different ZIKV isolates.

The amino acid sequence of ZIKV envelope glycoprotein (E), noted herein as “ZIKV E” is exemplified within the polyprotein amino acid sequence found in GenBank as accession number ALU33341.1 (See also SEQ ID NO: 353). The term also encompasses ZIKV E or a fragment thereof coupled to, for example, a histidine tag (e.g. see accession number ALU33341.1 with histidine tags (SEQ ID NOs: 354 and 355), mouse or human Fc, or a signal sequence. The amino acid sequence of ZIKV E is also shown in SEQ ID NO: 376. The E protein escape mutation for H4H25703N is shown at position 302 of SEQ ID NO: 377 (S302F). The E protein escape mutations for H4H25619P are shown at position 311 (T311I) and position 369 (K369E) of SEQ ID NO: 378.

The term “ZIKV infection”, or “ZIKV infection”, as used herein refers to the disease or condition resulting from exposure to the virus (e.g. after being bitten by a mosquito harboring the virus), or to an infected animal, or to an infected human patient, or contact with the bodily fluids or tissues from an animal or human patient having a ZIKV infection. The “symptoms associated with a ZIKV infection” include fever, headache, arthralgia, myalgia and a maculopapular rash. The “condition resulting from exposure to the virus”, or “the condition associated with exposure to the virus” also includes microcephaly (or developmental abnormalities) of a fetus in a pregnant woman who was infected with the virus after being bitten by a mosquito harboring the virus. Another “condition resulting from exposure to the virus”, or “condition associated with exposure to the virus” includes Guillain-Barré Syndrome.

The term “antibody”, as used herein, is intended to refer to immunoglobulin molecules comprised of four polypeptide chains, two heavy (H) chains and two light (L) chains inter-connected by disulfide bonds (i.e., “full antibody molecules”), as well as multimers thereof (e.g. IgM) or antigen-binding fragments thereof. Each heavy chain is comprised of a heavy chain variable region (“HCVR” or “V_(H)”) and a heavy chain constant region (comprised of domains C_(H)1, C_(H)2 and C_(H)3). Each light chain is comprised of a light chain variable region (“LCVR or “V_(L)”) and a light chain constant region (C_(L)). The V_(H) and V_(L) regions can be further subdivided into regions of hypervariability, termed complementarity determining regions (CDR), interspersed with regions that are more conserved, termed framework regions (FR). Each V_(H) and V_(L) is composed of three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. In certain embodiments of the invention, the FRs of the antibody (or antigen binding fragment thereof) may be identical to the human germline sequences, or may be naturally or artificially modified. An amino acid consensus sequence may be defined based on a side-by-side analysis of two or more CDRs.

Substitution of one or more CDR residues or omission of one or more CDRs is also possible. Antibodies have been described in the scientific literature in which one or two CDRs can be dispensed with for binding. Padlan et al. (1995 FASEB J. 9:133-139) analyzed the contact regions between antibodies and their antigens, based on published crystal structures, and concluded that only about one fifth to one third of CDR residues actually contact the antigen. Padlan also found many antibodies in which one or two CDRs had no amino acids in contact with an antigen (see also, Vajdos et al. 2002 J Mol Biol 320:415-428).

CDR residues not contacting antigen can be identified based on previous studies (for example residues H60-H65 in CDRH2 are often not required), from regions of Kabat CDRs lying outside Chothia CDRs, by molecular modeling and/or empirically. If a CDR or residue(s) thereof is omitted, it is usually substituted with an amino acid occupying the corresponding position in another human antibody sequence or a consensus of such sequences. Positions for substitution within CDRs and amino acids to substitute can also be selected empirically. Empirical substitutions can be conservative or non-conservative substitutions.

The fully human anti-ZIKV monoclonal antibodies disclosed herein may comprise one or more amino acid substitutions, insertions and/or deletions in the framework and/or CDR regions of the heavy and light chain variable domains as compared to the corresponding germline sequences. Such mutations can be readily ascertained by comparing the amino acid sequences disclosed herein to germline sequences available from, for example, public antibody sequence databases. The present invention includes antibodies, and antigen-binding fragments thereof, which are derived from any of the amino acid sequences disclosed herein, wherein one or more amino acids within one or more framework and/or CDR regions are mutated to the corresponding residue(s) of the germline sequence from which the antibody was derived, or to the corresponding residue(s) of another human germline sequence, or to a conservative amino acid substitution of the corresponding germline residue(s) (such sequence changes are referred to herein collectively as “germline mutations”). A person of ordinary skill in the art, starting with the heavy and light chain variable region sequences disclosed herein, can easily produce numerous antibodies and antigen-binding fragments which comprise one or more individual germline mutations or combinations thereof. In certain embodiments, all of the framework and/or CDR residues within the V_(H) and/or V_(L) domains are mutated back to the residues found in the original germline sequence from which the antibody was derived. In other embodiments, only certain residues are mutated back to the original germline sequence, e.g., only the mutated residues found within the first 8 amino acids of FR1 or within the last 8 amino acids of FR4, or only the mutated residues found within CDR1, CDR2 or CDR3. In other embodiments, one or more of the framework and/or CDR residue(s) are mutated to the corresponding residue(s) of a different germline sequence (i.e., a germline sequence that is different from the germline sequence from which the antibody was originally derived). Furthermore, the antibodies of the present invention may contain any combination of two or more germline mutations within the framework and/or CDR regions, e.g., wherein certain individual residues are mutated to the corresponding residue of a particular germline sequence while certain other residues that differ from the original germline sequence are maintained or are mutated to the corresponding residue of a different germline sequence. Once obtained, antibodies and antigen-binding fragments that contain one or more germline mutations can be easily tested for one or more desired property such as, improved binding specificity, increased binding affinity, improved or enhanced antagonistic or agonistic biological properties (as the case may be), reduced immunogenicity, etc. Antibodies and antigen-binding fragments obtained in this general manner are encompassed within the present invention.

The present invention also includes fully human anti-ZIKV monoclonal antibodies comprising variants of any of the HCVR, LCVR, and/or CDR amino acid sequences disclosed herein having one or more conservative substitutions. For example, the present invention includes anti-ZIKV antibodies having HCVR, LCVR, and/or CDR amino acid sequences with, e.g., 10 or fewer, 8 or fewer, 6 or fewer, 4 or fewer, etc. conservative amino acid substitutions relative to any of the HCVR, LCVR, and/or CDR amino acid sequences disclosed herein.

The term “human antibody”, as used herein, is intended to include antibodies having variable and constant regions derived from human germline immunoglobulin sequences. The human mAbs of the invention may include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo), for example in the CDRs and in particular CDR3. However, the term “human antibody”, as used herein, is not intended to include mAbs in which CDR sequences derived from the germline of another mammalian species (e.g., mouse), have been grafted onto human FR sequences. The term includes antibodies recombinantly produced in a non-human mammal, or in cells of a non-human mammal. The term is not intended to include antibodies isolated from or generated in a human subject.

The term “recombinant”, as used herein, refers to antibodies or antigen-binding fragments thereof of the invention created, expressed, isolated or obtained by technologies or methods known in the art as recombinant DNA technology which include, e.g., DNA splicing and transgenic expression. The term refers to antibodies expressed in a non-human mammal (including transgenic non-human mammals, e.g., transgenic mice), or a cell (e.g., CHO cells) expression system or isolated from a recombinant combinatorial human antibody library.

The term “specifically binds,” or “binds specifically to”, or the like, means that an antibody or antigen-binding fragment thereof forms a complex with an antigen that is relatively stable under physiologic conditions. Specific binding can be characterized by an equilibrium dissociation constant of at least about 1×10⁻⁷ M or less (e.g., a smaller K_(D) denotes a tighter binding). Methods for determining whether two molecules specifically bind are well known in the art and include, for example, equilibrium dialysis, surface plasmon resonance, and the like. As described herein, antibodies have been identified by surface plasmon resonance, e.g., BIACORE™, which bind specifically to ZIKV. Moreover, multi-specific antibodies that bind to one domain in ZIKV and one or more additional antigens or a bi-specific that binds to two different regions of ZIKV are nonetheless considered antibodies that “specifically bind”, as used herein.

The term “high affinity” antibody refers to those mAbs having a binding affinity to ZIKV, expressed as K_(D), of at least 10⁻⁷ M; preferably 10⁻⁸M; more preferably 10⁻⁹M, even more preferably 10⁻¹⁰ M, even more preferably 10⁻¹¹ M, even more preferably 10⁻¹² M, as measured by surface plasmon resonance, e.g., BIACORE™ or solution-affinity ELISA.

By the term “slow off rate”, “Koff” or “kd” is meant an antibody that dissociates from ZIKV, or a virus like particle expressing the ZIKV E, with a rate constant of 1×10⁻³ s⁻¹ or less, preferably 1×10⁻⁴s⁻¹ or less, as determined by surface plasmon resonance, e.g., BIACORE™.

The terms “antigen-binding portion” of an antibody, “antigen-binding fragment” of an antibody, and the like, as used herein, include any naturally occurring, enzymatically obtainable, synthetic, or genetically engineered polypeptide or glycoprotein that specifically binds an antigen to form a complex. The terms “antigen-binding fragment” of an antibody, or “antibody fragment”, as used herein, refers to one or more fragments of an antibody that retain the ability to bind to ZIKV.

In specific embodiments, antibody or antibody fragments of the invention may be conjugated to a moiety such a ligand or a therapeutic moiety (“immunoconjugate”), such as an anti-viral drug, a second anti-ZIKV antibody, or any other therapeutic moiety useful for treating an infection caused by ZIKV.

An “isolated antibody”, as used herein, is intended to refer to an antibody that is substantially free of other antibodies (Abs) having different antigenic specificities (e.g., an isolated antibody that specifically binds ZIKV, or a fragment thereof, is substantially free of Abs that specifically bind antigens other than ZIKV.

A “blocking antibody” or a “neutralizing antibody”, as used herein (or an “antibody that neutralizes ZIKV activity” or “antagonist antibody”), is intended to refer to an antibody whose binding to ZIKV results in inhibition of at least one biological activity of ZIKV. For example, an antibody of the invention may prevent or block ZIKV attachment to, fusion with, and/or entry into a host cell. In addition, a “neutralizing antibody” is one that can neutralize, i.e., prevent, inhibit, reduce, impede or interfere with, the ability of a pathogen to initiate and/or perpetuate an infection in a host. The terms “neutralizing antibody” and “an antibody that neutralizes” or “antibodies that neutralize” are used interchangeably herein. These antibodies can be used, alone or in combination, as prophylactic or therapeutic agents with other anti-viral agents upon appropriate formulation, or in association with active vaccination, or as a diagnostic tool.

“Antibody-dependent-enhancement” or “ADE” is a mechanism by which a virus, when bound to antiviral antibodies enters cells having Fc receptors, leading to increased infectivity in the cells. ADE is common in cells cultured in the laboratory, but rarely occurs in vivo except for infection with dengue virus, which is a member of the Flaviviridae family. This virus can use this mechanism to infect macrophages, causing a normally mild viral infection to become life-threatening.

The term “surface plasmon resonance”, as used herein, refers to an optical phenomenon that allows for the analysis of real-time biomolecular interactions by detection of alterations in protein concentrations within a biosensor matrix, for example using the BIACORE™ system (Pharmacia Biosensor AB, Uppsala, Sweden and Piscataway, N.J.).

The term “K_(D)”, as used herein, is intended to refer to the equilibrium dissociation constant of a particular antibody-antigen interaction.

The term “epitope” refers to an antigenic determinant that interacts with a specific antigen-binding site in the variable region of an antibody molecule known as a paratope. A single antigen may have more than one epitope. Thus, different antibodies may bind to different areas on an antigen and may have different biological effects. The term “epitope” also refers to a site on an antigen to which B and/or T cells respond. It also refers to a region of an antigen that is bound by an antibody. Epitopes may be defined as structural or functional. Functional epitopes are generally a subset of the structural epitopes and have those residues that directly contribute to the affinity of the interaction. Epitopes may also be conformational, that is, composed of non-linear amino acids. In certain embodiments, epitopes may include determinants that are chemically active surface groupings of molecules such as amino acids, sugar side chains, phosphoryl groups, or sulfonyl groups, and, in certain embodiments, may have specific three-dimensional structural characteristics, and/or specific charge characteristics.

The term “cross-competes”, as used herein, means an antibody or antigen-binding fragment thereof binds to an antigen and inhibits or blocks the binding of another antibody or antigen-binding fragment thereof. The term also includes competition between two antibodies in both orientations, i.e., a first antibody that binds and blocks binding of second antibody and vice-versa. In certain embodiments, the first antibody and second antibody may bind to the same epitope. Alternatively, the first and second antibodies may bind to different, but overlapping epitopes such that binding of one inhibits or blocks the binding of the second antibody, e.g., via steric hindrance. Cross-competition between antibodies may be measured by methods known in the art, for example, by a real-time, label-free bio-layer interferometry assay. To determine if a test antibody cross-competes with a reference anti-ZIKV antibody of the invention, the reference antibody is allowed to bind to an ZIKV E or peptide under saturating conditions. Next, the ability of a test antibody to bind to the ZIKV E is assessed. If the test antibody is able to bind to ZIKV E following saturation binding with the reference anti-ZIKV E antibody, it can be concluded that the test antibody binds to a different epitope than the reference anti-ZIKV antibody. On the other hand, if the test antibody is not able to bind to the ZIKV E following saturation binding with the reference anti-ZIKV E antibody, then the test antibody may bind to the same epitope as the epitope bound by the reference anti-ZIKV E antibody of the invention.

The term “substantial identity” or “substantially identical,” when referring to a nucleic acid or fragment thereof, indicates that, when optimally aligned with appropriate nucleotide insertions or deletions with another nucleic acid (or its complementary strand), there is nucleotide sequence identity in at least about 90%, and more preferably at least about 95%, 96%, 97%, 98% or 99% of the nucleotide bases, as measured by any well-known algorithm of sequence identity, such as FASTA, BLAST or GAP, as discussed below. A nucleic acid molecule having substantial identity to a reference nucleic acid molecule may, in certain instances, encode a polypeptide having the same or substantially similar amino acid sequence as the polypeptide encoded by the reference nucleic acid molecule.

As applied to polypeptides, the term “substantial similarity” or “substantially similar” means that two peptide sequences, when optimally aligned, such as by the programs GAP or BESTFIT using default gap weights, share at least 90% sequence identity, even more preferably at least 95%, 98% or 99% sequence identity. Preferably, residue positions, which are not identical, differ by conservative amino acid substitutions. A “conservative amino acid substitution” is one in which an amino acid residue is substituted by another amino acid residue having a side chain (R group) with similar chemical properties (e.g., charge or hydrophobicity). In general, a conservative amino acid substitution will not substantially change the functional properties of a protein. In cases where two or more amino acid sequences differ from each other by conservative substitutions, the percent or degree of similarity may be adjusted upwards to correct for the conservative nature of the substitution. Means for making this adjustment are well known to those of skill in the art. See, e.g., Pearson (1994) Methods Mol. Biol. 24: 307-331, which is herein incorporated by reference. Examples of groups of amino acids that have side chains with similar chemical properties include 1) aliphatic side chains: glycine, alanine, valine, leucine and isoleucine; 2) aliphatic-hydroxyl side chains: serine and threonine; 3) amide-containing side chains: asparagine and glutamine; 4) aromatic side chains: phenylalanine, tyrosine, and tryptophan; 5) basic side chains: lysine, arginine, and histidine; 6) acidic side chains: aspartate and glutamate, and 7) sulfur-containing side chains: cysteine and methionine. Preferred conservative amino acids substitution groups are: valine-leucine-isoleucine, phenylalanine-tyrosine, lysine-arginine, alanine-valine, glutamate-aspartate, and asparagine-glutamine. Alternatively, a conservative replacement is any change having a positive value in the PAM250 log-likelihood matrix disclosed in Gonnet et al. (1992) Science 256: 1443 45, herein incorporated by reference. A “moderately conservative” replacement is any change having a nonnegative value in the PAM250 log-likelihood matrix.

Sequence similarity for polypeptides is typically measured using sequence analysis software. Protein analysis software matches similar sequences using measures of similarity assigned to various substitutions, deletions and other modifications, including conservative amino acid substitutions. For instance, GCG software contains programs such as GAP and BESTFIT which can be used with default parameters to determine sequence homology or sequence identity between closely related polypeptides, such as homologous polypeptides from different species of organisms or between a wild type protein and a mutein thereof. See, e.g., GCG Version 6.1. Polypeptide sequences also can be compared using FASTA with default or recommended parameters; a program in GCG Version 6.1. FASTA (e.g., FASTA2 and FASTA3) provides alignments and percent sequence identity of the regions of the best overlap between the query and search sequences (Pearson (2000) supra). Another preferred algorithm when comparing a sequence of the invention to a database containing a large number of sequences from different organisms is the computer program BLAST, especially BLASTP or TBLASTN, using default parameters. See, e.g., Altschul et al. (1990) J. Mol. Biol. 215: 403-410 and (1997) Nucleic Acids Res. 25:3389-3402, each of which is herein incorporated by reference.

By the phrase “therapeutically effective amount” is meant an amount that produces the desired effect for which it is administered. The exact amount will depend on the purpose of the treatment, and will be ascertainable by one skilled in the art using known techniques (see, for example, Lloyd (1999) The Art, Science and Technology of Pharmaceutical Compounding).

As used herein, the term “subject” refers to an animal, preferably a mammal, more preferably a human, in need of amelioration, prevention and/or treatment of a disease or disorder such as a viral infection. The subject may have a ZIKV infection or is predisposed to developing a ZIKV infection. Subjects “predisposed to developing a ZIKV infection”, or subjects “who may be at elevated risk for contracting a ZIKV infection”, are those subjects with compromised immune systems because of autoimmune disease, those persons receiving immunosuppressive therapy (for example, following organ transplant), those persons afflicted with human immunodeficiency syndrome (HIV) or acquired immune deficiency syndrome (AIDS), pregnant females who have been exposed to, or who may become exposed to the ZIKV if living in, or visiting an area that has an outbreak of ZIKV, in addition to a woman who lives in, or is visiting an area known to have a ZIKV outbreak and is considering conceiving a child, certain forms of anemia that deplete or destroy white blood cells, those persons receiving radiation or chemotherapy, or those persons afflicted with an inflammatory disorder. Additionally, subjects of extreme young or old age are at increased risk. Any person who comes into physical contact or close physical proximity with an infected animal, or human patient, or is exposed to bodily fluids or tissues from an infected animal or human patient, has an increased risk of developing a ZIKV infection. Moreover, a subject is at risk of contracting an ZIKV infection due to proximity to an outbreak of the disease, e.g. subject resides in a densely-populated city or in close proximity to subjects having confirmed or suspected infections of ZIKV, or choice of employment, e.g. hospital worker, pharmaceutical researcher, or an individual who has visited or who is planning to visit an area or country known to have or suspected to have an outbreak of ZIKV. There is also an increased risk of severe outcomes in a subject if they contract a ZIKV infection. When a pregnant woman is infected with ZIKV, there is an increased risk that the baby may be born with microcephaly or other developmental abnormalities. Accordingly, if a woman is pregnant, or is considering conceiving a child, and she is living in an area where there is a ZIKV outbreak, or visiting an area where there is a ZIKV outbreak, or is in an area that is known to have mosquitoes that harbor the ZIKV, she is at risk for contracting a ZIKV infection. There is also an increased risk of developing Guillain-Barré syndrome after exposure of a subject to ZIKV.

As used herein, the terms “treat”, “treating”, or “treatment” refer to the reduction or amelioration of the severity of at least one symptom or indication of ZIKV infection due to the administration of a therapeutic agent such as an antibody of the present invention to a subject in need thereof. The terms include inhibition of progression of disease or of worsening of infection. The terms also include positive prognosis of disease, i.e., the subject may be free of infection or may have reduced or no viral titers upon administration of a therapeutic agent such as an antibody of the present invention. The therapeutic agent may be administered at a therapeutic dose to the subject.

The terms “prevent”, “preventing” or “prevention” refer to inhibition of manifestation of ZIKV infection or any symptoms or indications of ZIKV infection upon administration of an antibody of the present invention. The term includes prevention of spread of infection in a subject exposed to the virus or at risk of having ZIKV infection.

As used herein, the term “anti-viral drug” refers to any anti-infective agent or therapy, whether it be a chemical moiety, or a biological therapy, used to treat, prevent, or ameliorate a viral infection in a subject. For example, in the present invention an anti-viral drug may include, but not be limited to, an antibody to ZIKV (in one embodiment the antibody to ZIKV may be different than those described herein), a vaccine for ZIKV, a direct-acting antiviral agent, and interferons (or other immune modulators). In the present invention, the infection to be treated is caused by a ZIKV.

General Description

ZIKV infection is generally a mild disease in healthy subjects, but pregnant women exposed to the virus are at risk of giving birth to an infant with microcephaly or other developmental abnormalities. The virus is a member of the Flaviviridae family.

The genome of the virus consists of a single strand of positive sense RNA of approximately 11 kb in length and encodes about 10 genes. Zika virions contain three structural proteins: a capsid protein (C), a membrane protein/premembrane protein (M/prM), and an envelope glycoprotein (E). The viral genome also encodes seven non-structural proteins.

Described herein are fully human antibodies and antigen-binding fragments thereof that specifically bind to ZIKV E and modulate the interaction of ZIKV with host cells. The anti-ZIKV E antibodies may bind to the ZIKV with high affinity. In certain embodiments, the antibodies of the present invention may prevent attachment of the virus to the cell, or may block fusion of the virus to the host cell membrane. In so doing, the antibodies block virus entry into the cell and as such inhibit or neutralize viral infection of host cells. In some embodiments, the antibodies may be useful for treating a subject suffering from a ZIKV infection, or a subject who is at risk for acquiring a ZIKV infection (e.g. a pregnant female who is living in, or visiting, a country that has a ZIKV outbreak). The antibodies when administered to a subject in need thereof may reduce the infection by a virus such as ZIKV in the subject. They may be used to decrease viral loads in a subject. They may be used alone or as adjunct therapy with other therapeutic moieties or modalities known in the art for treating a viral infection. The identified antibodies can be used prophylactically (before infection) to protect a mammal from infection, or can be used therapeutically (after infection is established) to ameliorate a previously established infection, or to ameliorate at least one symptom associated with the infection.

The full-length amino acid sequence of an exemplary ZIKV polyprotein is shown in GenBank as accession number ALU33341.1 and also in SEQ ID NO: 353. A fragment of the ZIKV E, may be coupled to a histidine tag, such as shown in SEQ ID NOs: 354 or 355. In certain embodiments, the antibodies of the invention are obtained from mice immunized with a primary immunogen, such as a full-length ZIKV E co-expressed with prM, or with a recombinant form of ZIKV E or fragments thereof, or particles comprised of prM and E followed by immunization with a secondary immunogen, or with an immunogenically active fragment of ZIKV E. In certain embodiments, the antibodies are obtained from mice immunized with DNA encoding the ZIKV prM/E.

The immunogen may be a biologically active and/or immunogenic fragment of ZIKV E or DNA encoding the active fragment thereof. The fragment may be derived from any region of the viral E. The peptides may be modified to include addition or substitution of certain residues for tagging or for purposes of conjugation to carrier molecules, such as, KLH. For example, a cysteine may be added at either the N terminal or C terminal end of a peptide, or a linker sequence may be added to prepare the peptide for conjugation to, for example, KLH for immunization.

Certain anti-ZIKV antibodies of the present invention are able to bind to and neutralize the activity of ZIKV, as determined by in vitro or in vivo assays. The ability of the antibodies of the invention to bind to and neutralize the activity of ZIKV and thus the attachment and/or entry of the virus into a host cell followed by the ensuing viral infection, may be measured using any standard method known to those skilled in the art, including binding assays, or activity assays, as described herein.

Non-limiting, exemplary in vitro assays for measuring binding activity are illustrated in Example 3, herein. In Example 3, the binding of anti-ZIKV E was determined by evaluating binding to virus like particles (VLPs) produced in cells expressing prM/E. In Example 4 the equilibrium dissociation constants were determined using real-time surface plasmon resonance in a Biacore 4000 instrument. Neutralization assays were used to determine the effect of anti-zika antibodies on infectivity of ZIKV in Example 5. Cross-competition assays were conducted in Example 6 to determine cross reactivity of anti-zika antibodies.

The antibodies specific for ZIKV E may contain no additional labels or moieties, or they may contain an N-terminal or C-terminal label or moiety. In one embodiment, the label or moiety is biotin. In a binding assay, the location of a label (if any) may determine the orientation of the peptide relative to the surface upon which the peptide is bound. For example, if a surface is coated with avidin, a peptide containing an N-terminal biotin will be oriented such that the C-terminal portion of the peptide will be distal to the surface. In one embodiment, the label may be a radionuclide, a fluorescent dye or a MRI-detectable label. In certain embodiments, such labeled antibodies may be used in diagnostic assays including imaging assays.

Antigen-Binding Fragments of Antibodies

Unless specifically indicated otherwise, the term “antibody,” as used herein, shall be understood to encompass antibody molecules comprising two immunoglobulin heavy chains and two immunoglobulin light chains (i.e., “full antibody molecules”) as well as antigen-binding fragments thereof. The terms “antigen-binding portion” of an antibody, “antigen-binding fragment” of an antibody, and the like, as used herein, include any naturally occurring, enzymatically obtainable, synthetic, or genetically engineered polypeptide or glycoprotein that specifically binds an antigen to form a complex. The terms “antigen-binding fragment” of an antibody, or “antibody fragment”, as used herein, refers to one or more fragments of an antibody that retain the ability to specifically bind to ZIKV. An antibody fragment may include a Fab fragment, a F(ab′)₂ fragment, a Fv fragment, a dAb fragment, a fragment containing a CDR, or an isolated CDR. In certain embodiments, the term “antigen-binding fragment” refers to a polypeptide fragment of a multi-specific antigen-binding molecule. Antigen-binding fragments of an antibody may be derived, e.g., from full antibody molecules using any suitable standard techniques such as proteolytic digestion or recombinant genetic engineering techniques involving the manipulation and expression of DNA encoding antibody variable and (optionally) constant domains. Such DNA is known and/or is readily available from, e.g., commercial sources, DNA libraries (including, e.g., phage-antibody libraries), or can be synthesized. The DNA may be sequenced and manipulated chemically or by using molecular biology techniques, for example, to arrange one or more variable and/or constant domains into a suitable configuration, or to introduce codons, create cysteine residues, modify, add or delete amino acids, etc.

Non-limiting examples of antigen-binding fragments include: (i) Fab fragments; (ii) F(ab′)2 fragments; (iii) Fd fragments; (iv) Fv fragments; (v) single-chain Fv (scFv) molecules; (vi) dAb fragments; and (vii) minimal recognition units consisting of the amino acid residues that mimic the hypervariable region of an antibody (e.g., an isolated complementarity determining region (CDR) such as a CDR3 peptide), or a constrained FR3-CDR3-FR4 peptide. Other engineered molecules, such as domain-specific antibodies, single domain antibodies, domain-deleted antibodies, chimeric antibodies, CDR-grafted antibodies, diabodies, triabodies, tetrabodies, minibodies, nanobodies (e.g. monovalent nanobodies, bivalent nanobodies, etc.), small modular immunopharmaceuticals (SMIPs), and shark variable IgNAR domains, are also encompassed within the expression “antigen-binding fragment,” as used herein.

An antigen-binding fragment of an antibody will typically comprise at least one variable domain. The variable domain may be of any size or amino acid composition and will generally comprise at least one CDR, which is adjacent to or in frame with one or more framework sequences. In antigen-binding fragments having a V_(H) domain associated with a V_(L) domain, the V_(H) and V_(L) domains may be situated relative to one another in any suitable arrangement. For example, the variable region may be dimeric and contain V_(H)-V_(H), V_(H)-V_(L) or V_(L)-V_(L) dimers. Alternatively, the antigen-binding fragment of an antibody may contain a monomeric V_(H) or V_(L) domain.

In certain embodiments, an antigen-binding fragment of an antibody may contain at least one variable domain covalently linked to at least one constant domain. Non-limiting, exemplary configurations of variable and constant domains that may be found within an antigen-binding fragment of an antibody of the present invention include: (i) V_(H)-C_(H)1; (ii) V_(H)-C_(H)2; (iii) V_(H)-C_(H)3; (iv) V_(H)-C_(H)1-C_(H)2; (V) V_(H)-C_(H)1-C_(H)2-C_(H)3; V_(H)-C_(H)2-C_(H)3; V_(H)-C_(L); V_(L)-C_(H)1; (ix) V_(L)-C_(H)2; (x) V_(L)-C_(H)3; (xi) V_(L)-C_(H)1-C_(H)2; (xii) V_(L)-C_(H)1-C_(H)2-C_(H)3; V_(L)-C_(H)2-C_(H)3; and (xiv) V_(L)-C_(L). In any configuration of variable and constant domains, including any of the exemplary configurations listed above, the variable and constant domains may be either directly linked to one another or may be linked by a full or partial hinge or linker region. A hinge region may consist of at least 2 (e.g., 5, 10, 15, 20, 40, 60 or more) amino acids, which result in a flexible or semi-flexible linkage between adjacent variable and/or constant domains in a single polypeptide molecule. Moreover, an antigen-binding fragment of an antibody of the present invention may comprise a homo-dimer or hetero-dimer (or other multimer) of any of the variable and constant domain configurations listed above in non-covalent association with one another and/or with one or more monomeric V_(H) or V_(L) domain (e.g., by disulfide bond(s)).

As with full antibody molecules, antigen-binding fragments may be mono-specific or multi-specific (e.g., bi-specific). A multi-specific antigen-binding fragment of an antibody will typically comprise at least two different variable domains, wherein each variable domain is capable of specifically binding to a separate antigen or to a different epitope on the same antigen. Any multi-specific antibody format, including the exemplary bi-specific antibody formats disclosed herein, may be adapted for use in the context of an antigen-binding fragment of an antibody of the present invention using routine techniques available in the art.

Preparation of Human Antibodies

Methods for generating human antibodies in transgenic mice are known in the art. Any such known methods can be used in the context of the present invention to make human antibodies that specifically bind to ZIKV E. An immunogen comprising any one of the following can be used to generate antibodies to ZIKV. In certain embodiments, the antibodies of the invention are obtained from mice immunized with a fragment of the full-length ZIKV polyprotein (See, for example, GenBank accession numbers ALU33341.1 (SEQ ID NO: 353)), consisting of prM/E or a fragment thereof. Alternatively, the ZIKV E or a fragment thereof may be produced using standard biochemical techniques and modified and used as immunogen. In one embodiment, the immunogen is a recombinantly produced ZIKV E or fragment thereof. In certain embodiments of the invention, the immunogen may be a commercially available ZIKV E. In certain embodiments, one or more booster injections may be administered. In certain embodiments, the booster injections may comprise one or more commercially available ZIKV envelope glycoproteins. In certain embodiments, the immunogen may be a recombinant ZIKV E expressed in E. coli or in any other eukaryotic or mammalian cells such as Chinese hamster ovary (CHO) cells.

Using VELOCIMMUNE® technology (see, for example, U.S. Pat. No. 6,596,541, Regeneron Pharmaceuticals, VELOCIMMUNE®) or any other known method for generating monoclonal antibodies, high affinity chimeric antibodies to ZIKV E are initially isolated having a human variable region and a mouse constant region. The VELOCIMMUNE® technology involves generation of a transgenic mouse having a genome comprising human heavy and light chain variable regions operably linked to endogenous mouse constant region loci such that the mouse produces an antibody comprising a human variable region and a mouse constant region in response to antigenic stimulation. The DNA encoding the variable regions of the heavy and light chains of the antibody are isolated and operably linked to DNA encoding the human heavy and light chain constant regions. The DNA is then expressed in a cell capable of expressing the fully human antibody.

Generally, a VELOCIMMUNE® mouse is challenged with the antigen of interest, and lymphatic cells (such as B-cells) are recovered from the mice that express antibodies. The lymphatic cells may be fused with a myeloma cell line to prepare immortal hybridoma cell lines, and such hybridoma cell lines are screened and selected to identify hybridoma cell lines that produce antibodies specific to the antigen of interest. DNA encoding the variable regions of the heavy chain and light chain may be isolated and linked to desirable isotypic constant regions of the heavy chain and light chain. Such an antibody protein may be produced in a cell, such as a CHO cell. Alternatively, DNA encoding the antigen-specific chimeric antibodies or the variable domains of the light and heavy chains may be isolated directly from antigen-specific lymphocytes.

Initially, high affinity chimeric antibodies are isolated having a human variable region and a mouse constant region. As in the experimental section below, the antibodies are characterized and selected for desirable characteristics, including affinity, selectivity, epitope, etc. The mouse constant regions are replaced with a desired human constant region to generate the fully human antibody of the invention, for example wild-type or modified IgG1 or IgG4. While the constant region selected may vary according to specific use, high affinity antigen-binding and target specificity characteristics reside in the variable region.

Bioequivalents

The anti-ZIKV E antibodies and antibody fragments of the present invention encompass proteins having amino acid sequences that vary from those of the described antibodies, but that retain the ability to react with ZIKV. Such variant antibodies and antibody fragments comprise one or more additions, deletions, or substitutions of amino acids when compared to parent sequence, but exhibit biological activity that is essentially equivalent to that of the described antibodies. Likewise, the antibody-encoding DNA sequences of the present invention encompass sequences that comprise one or more additions, deletions, or substitutions of nucleotides when compared to the disclosed sequence, but that encode an antibody or antibody fragment that is essentially bioequivalent to an antibody or antibody fragment of the invention.

Two antigen-binding proteins, or antibodies, are considered bioequivalent if, for example, they are pharmaceutical equivalents or pharmaceutical alternatives whose rate and extent of absorption do not show a significant difference when administered at the same molar dose under similar experimental conditions, either single dose or multiple doses. Some antibodies will be considered equivalents or pharmaceutical alternatives if they are equivalent in the extent of their absorption but not in their rate of absorption and yet may be considered bioequivalent because such differences in the rate of absorption are intentional and are reflected in the labeling, are not essential to the attainment of effective body drug concentrations on, e.g., chronic use, and are considered medically insignificant for the particular drug product studied.

In one embodiment, two antigen-binding proteins are bioequivalent if there are no clinically meaningful differences in their safety, purity, or potency.

In one embodiment, two antigen-binding proteins are bioequivalent if a patient can be switched one or more times between the reference product and the biological product without an expected increase in the risk of adverse effects, including a clinically significant change in immunogenicity, or diminished effectiveness, as compared to continued therapy without such switching.

In one embodiment, two antigen-binding proteins are bioequivalent if they both act by a common mechanism or mechanisms of action for the condition or conditions of use, to the extent that such mechanisms are known.

Bioequivalence may be demonstrated by in vivo and/or in vitro methods. Bioequivalence measures include, e.g., (a) an in vivo test in humans or other mammals, in which the concentration of the antibody or its metabolites is measured in blood, plasma, serum, or other biological fluid as a function of time; (b) an in vitro test that has been correlated with and is reasonably predictive of human in vivo bioavailability data; (c) an in vivo test in humans or other mammals in which the appropriate acute pharmacological effect of the antibody (or its target) is measured as a function of time; and (d) in a well-controlled clinical trial that establishes safety, efficacy, or bioavailability or bioequivalence of an antibody.

Bioequivalent variants of the antibodies of the invention may be constructed by, for example, making various substitutions of residues or sequences or deleting terminal or internal residues or sequences not needed for biological activity. For example, cysteine residues not essential for biological activity can be deleted or replaced with other amino acids to prevent formation of unnecessary or incorrect intramolecular disulfide bridges upon renaturation. In other contexts, bioequivalent antibodies may include antibody variants comprising amino acid changes, which modify the glycosylation characteristics of the antibodies, e.g., mutations that eliminate or remove glycosylation.

Anti-ZIKV Antibodies Comprising Fc Variants

According to certain embodiments of the present invention, anti-ZIKV antibodies comprising an Fc domain comprising one or more mutations that diminish antibody binding to the FcRn receptor may be prepared.

In one embodiment, the present invention includes anti-ZIKV antibodies comprising a chimeric heavy chain constant (C_(H)) region, wherein the chimeric C_(H) region comprises segments derived from the C_(H) regions of more than one immunoglobulin isotype. For example, the antibodies of the invention may comprise a chimeric C_(H) region comprising part or all of a C_(H)2 domain derived from a human IgG1, human IgG2 or human IgG4 molecule, combined with part or all of a C_(H)3 domain derived from a human IgG1, human IgG2 or human IgG4 molecule. According to certain embodiments, the antibodies of the invention comprise a chimeric C_(H) region having a chimeric hinge region. For example, a chimeric hinge may comprise an “upper hinge” amino acid sequence (amino acid residues from positions 216 to 227 according to EU numbering) derived from a human IgG1, a human IgG2 or a human IgG4 hinge region, combined with a “lower hinge” sequence (amino acid residues from positions 228 to 236 according to EU numbering) derived from a human IgG1, a human IgG2 or a human IgG4 hinge region. According to certain embodiments, the chimeric hinge region comprises amino acid residues derived from a human IgG1 or a human IgG4 upper hinge and amino acid residues derived from a human IgG2 lower hinge. An antibody comprising a chimeric C_(H) region as described herein may, in certain embodiments, exhibit modified Fc effector functions without adversely affecting the therapeutic or pharmacokinetic properties of the antibody. (See, e.g., U.S. Pat. No. 9,359,437, the disclosure of which is hereby incorporated by reference in its entirety).

In certain embodiments of the present invention, the modified Fc domain for use in the context of the present invention may comprise an IgG1 Fc comprising the amino acid sequence as shown in SEQ ID NO: 356. Alternatively, a modified Fc for use in the context of the present invention may comprise an IgG4 Fc comprising the amino acid sequence shown in SEQ ID NO: 357, or SEQ ID NO: 358. Non-limiting, exemplary modified Fc regions that can be used in the context of the present invention are set forth in U.S. Pat. No. 9,359,437, and in U.S. 62/140,350, the disclosures of which are hereby incorporated by reference in their entireties, as well as any functionally equivalent variants of the modified Fc regions set forth therein.

In certain embodiments, the present invention also includes anti-ZIKV E antibodies comprising an Fc domain having the following mutations: M131Y, S133T and T135E (based on the residues as numbered in SEQ ID NO: 358), wherein the mutation provides for extended serum half lives of the antibodies.

Other modified Fc domains and Fc modifications that can be used in the context of the present invention include any of the modifications as set forth in US 2014/0171623; U.S. Pat. No. 8,697,396; US 2014/0134162; WO 2014/043361, the disclosures of which are hereby incorporated by reference in their entireties. Methods of constructing antibodies or other antigen-binding fusion proteins comprising a modified Fc domain as described herein are known in the art.

Antibody-Dependent-Enhancement

Antibody-dependent enhancement (ADE) is a mechanism by which a virus, when bound to antiviral antibodies enters cells having Fc receptors, leading to increased infectivity in the cells. ADE has been demonstrated in vitro for many viruses (including ZIKV), but the only compelling data for ADE in man comes from dengue virus infections. This virus can use this mechanism to infect macrophages, causing a normally mild viral infection to become life-threatening. For example, an initial dengue virus infection is clinically manifested for most of the cases by dengue fever (DF), which is a self-limited febrile illness. Although rarely fatal, DF is characterized by often-severe disseminated body pain, headache, fever, rash, lymphadenopathy and leukopenia. Subsequent infection with a heterologous Dengue virus can lead to the much more severe to fatal disease of dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). It is hypothesized that the presence of antibodies to the serotype causing the primary infection enhances the infection by a heterologous serotype in secondary infections. During such secondary infection, with a different serotype of dengue virus, cross-reactive antibodies that are not neutralizing form virus-antibody complexes that are taken into monocytes and Langerhans cells (dendritic cells) and increase the number of infected cells. This leads to the activation of cytotoxic lymphocytes, which can result in plasma leakage and the hemorrhagic features characteristic of DHF and DSS. This antibody-dependent enhancement of infection is one reason why the development of a successful vaccine against dengue virus has proven to be so difficult. Although less frequent, DHF/DSS can occur after primary infection, so virus virulence and immune activation are also believed to contribute to the pathogenesis of the disease.

ZIKV infection occurs in areas previously exposed to dengue virus, which is closely related to ZIKV. Furthermore, it has recently been shown that plasma from patients immune to dengue virus shows substantial cross-reactivity to ZIKV. In addition, using a panel of human sera and antibodies that react with the dengue virus envelope protein, it was shown that these antibodies also react with ZIKV. Certain of these antibodies were able to bind ZIKV, but were unable to neutralize the virus, but instead promoted ADE in vitro.

The proposed mechanism by which ADE occurs is by binding the virus to the surface of cells that contain abundant FcγRs, but low levels of other viral attachment factors. This results in cell internalization in the absence of other viral attachment factors, initiating viral infection through the normal infection route.

In certain embodiments, the anti-ZIKV antibodies of the present invention comprise a modified Fc domain having reduced effector function. As used herein, a “modified Fc domain having reduced effector function” means any Fc portion of an immunoglobulin that has been modified, mutated, truncated, etc., relative to a wild-type, naturally occurring Fc domain such that a molecule comprising the modified Fc exhibits a reduction in the severity or extent of at least one effect selected from the group consisting of cell killing (e.g., ADCC and/or CDC), complement activation, phagocytosis and opsonization, relative to a comparator molecule comprising the wild-type, naturally occurring version of the Fc portion. In certain embodiments, a “modified Fc domain having reduced effector function” is an Fc domain with reduced or attenuated binding to an Fc receptor (e.g., FcγR).

Accordingly, in certain embodiments of the invention, the anti-ZIKV antibodies comprise modifications to the Fc region of the antibodies to allow for reduced binding to Fc receptors on macrophages and other cells bearing Fc receptors, while at the same time maintaining the ability to neutralize the virus, and in so doing act to prevent ADE from occurring while at the same time allowing for a decrease in viral infectivity through the normal viral attachment and/or neutralization of fusion.

According to certain embodiments, the modified Fc domain having reduced effector function is a variant IgG4 Fc comprising the amino acid sequence shown in either SEQ ID NO: 357 (without a YTE modification at positions 131, 133 and 135), or SEQ ID NO:358 (having a YTE modification at positions 131, 133 and 135), as described above. As such, an antibody having a variant IgG4 Fc without the YTE modification would not demonstrate antibody dependent enhancement and would not have an extended half-life (e.g. H4H25703N having a HC/LC of SEQ ID NOs: 367/368), whereas an antibody having a variant IgG4 Fc with a YTE modification (e.g. H4H25703 having a HC/LC of SEQ ID NOs: 369/368) would not demonstrate antibody dependent enhancement but would have an extended half-life. As such, Fc modifications can be made that result in either one, or both reduced effector function and longer serum half-life of an antibody, as compared to a wildtype IgG4 Fc.

In one aspect of the invention, the invention comprises a human antibody, an antibody variant, or an antigen binding fragment thereof, that neutralize ZIKV, wherein the antibody, antibody variant, or antigen binding fragment does not contribute to antibody-dependent enhancement of ZIKV infection. In one embodiment, the invention comprises a human antibody, an antibody variant, or an antigen binding fragment thereof, that neutralize ZIKV, wherein the antibody, antibody variant, or antigen binding fragment comprises a mutation in the Fc region, and wherein the mutation reduces binding of the antibody to an Fc receptor.

In another embodiment of the invention, the invention comprises a pharmaceutical composition comprising two or more human antibodies, or antigen binding fragments thereof that bind ZIKV E. The antibodies or antigen binding fragments may prevent attachment of the virus to the cell, or may prevent fusion of the virus to the host cell membrane and as such, prevent viral entry to the cell and replication within the cell and do not contribute to antibody-dependent enhancement of ZIKV infection.

Biological Characteristics of the Antibodies

In general, the antibodies of the present invention function by binding to ZIKV envelope glycoprotein (E). For example, the present invention includes antibodies and antigen-binding fragments of antibodies that bind ZIKV E (e.g., at 25° C. or at 37° C.) with a K_(D) of less than 10⁻⁷M, as measured by surface plasmon resonance, e.g., using the assay format as described herein. In certain embodiments, the antibodies or antigen-binding fragments thereof bind ZIKV E with a K_(D) of less than about 100 nM, less than about 50 nM, less than about 5 nM, less than about 1 nM, less than about 500 pM, less than 250 pM, less than about 100 pM, or less than about 1 pM, as measured by surface plasmon resonance, e.g., using the assay format as described herein, or a substantially similar assay.

The present invention also includes antibodies and antigen-binding fragments thereof that bind ZIKV with a dissociative half-life (t½) of greater than about 0.5 minutes as measured by surface plasmon resonance at 25° C., or greater than about 0.3 minutes as measured by surface plasmon resonance at 37° C. and may or may not demonstrate a change in dissociative half life (t½) at pH 5, or pH 6 relative to a pH of 7.4, e.g., using an assay format as defined herein, or a substantially similar assay. In certain embodiments, the antibodies or antigen-binding fragments of the present invention bind ZIKV with a t½ of greater than about 10 minutes, of greater than about 30 minutes, of greater than about 60 minutes, of greater than about 100 minutes, of greater than about 200 minutes, greater than about 300 minutes, greater than about 400 minutes, greater than about 500 minutes, greater than about 600 minutes, greater than about 700 minutes, greater than about 800 minutes, greater than about 900 minutes, or greater than about 1000 minutes as measured by surface plasmon resonance at 25° C., or at 37° C. e.g., using an assay format as defined herein (e.g., mAb-capture or antigen-capture format), or a substantially similar assay.

The present invention also includes antibodies or antigen-binding fragments thereof that neutralize the infectivity of ZIKV for its host cells. In some embodiments, the antibodies exhibit a neutralization potency against ZIKV with an IC₅₀ ranging from about 10⁻¹¹M to about 10⁻⁹ M. The antibodies of the invention also cross react with ZIKV strains including MR766 (Uganda 1947), PRVABC59 (Puerto Rico 2015), and FLR (Colombia 2015). The antibodies of the invention also bind to VLPs derived from cells expressing ZIKV prM/E with an EC₅₀ ranging from about 80 pM to about 150 nM. Furthermore, the antibodies of the invention cross-compete with other antibodies that bind ZIKV E.

In one embodiment, the present invention provides an isolated recombinant antibody or antigen-binding fragment thereof that specifically binds to ZIKV and/or a ZIKV E, wherein the antibody has one or more of the following characteristics:

(a) comprises three heavy chain complementarity determining regions (CDRs) (HCDR1, HCDR2 and HCDR3) contained within any one of the heavy chain variable region (HCVR) sequences selected from the group consisting of SEQ ID NOs: 2, 18, 34, 50, 66, 82, 98, 114, 130, 146, 162, 178, 194, 210, 226, 242, 258, 274, 290, 306, 322 and 338; and three light chain CDRs (LCDR1, LCDR2 and LCDR3) contained within any one of the light chain variable region (LCVR) sequences selected from the group consisting of SEQ ID NOs: 10, 26, 42, 58, 74, 90, 106, 122, 138, 154, 170, 186, 202, 218, 234, 250, 266, 282, 298, 314, 330 and 346;

(b) is a fully human monoclonal antibody;

(c) binds to a VLP expressing Zika prM/E with an EC₅₀ ranging from about 80 pM to about 150 nM;

(d) binds to ZIKV E with a dissociation constant (K_(D)) of less than 10⁻⁷M, as measured in a surface plasmon resonance assay;

(e) may or may not demonstrate a change in dissociative half-life (t½) at pH 5 or pH 6 relative to pH 7.4;

(f) demonstrates neutralization of ZIKV with an IC₅₀ ranging from about 10⁻¹¹ M to about 10⁻⁹M;

(g) demonstrates a protective effect in vivo in a ZIKV infected animal;

(h) cross-competes with a reference antibody, wherein the reference antibody comprises a heavy chain variable region (HCVR) and a light chain variable region (LCVR) amino acid sequence selected from the group consisting of any of the HCVR and LCVR amino acid sequences of Table 1.

The antibodies of the present invention may possess one or more of the aforementioned biological characteristics, or any combinations thereof. Certain of the properties of the antibodies of the invention are summarized below. Other biological characteristics of the antibodies of the present invention will be evident to a person of ordinary skill in the art from a review of the present disclosure including the working Examples herein.

Epitope Mapping and Related Technologies

The present invention includes anti-ZIKV antibodies that interact with one or more amino acids found within the E of ZIKV. The epitope to which the antibodies bind may consist of a single contiguous sequence of 3 or more (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or more) amino acids located within ZIKV E (e.g. a linear epitope in a domain). Alternatively, the epitope may consist of a plurality of non-contiguous amino acids (or amino acid sequences) located within the ZIKV E (e.g. a conformational epitope).

Various techniques known to persons of ordinary skill in the art can be used to determine whether an antibody “interacts with one or more amino acids” within a polypeptide or protein. Exemplary techniques include, for example, routine cross-blocking assays, such as that described in Antibodies, Harlow and Lane (Cold Spring Harbor Press, Cold Spring Harbor, N.Y.). Other methods include alanine scanning mutational analysis, peptide blot analysis (Reineke (2004) Methods Mol. Biol. 248: 443-63), peptide cleavage analysis crystallographic studies and NMR analysis. In addition, methods such as epitope excision, epitope extraction and chemical modification of antigens can be employed (Tomer (2000) Prot. Sci. 9: 487-496). Another method that can be used to identify the amino acids within a polypeptide with which an antibody interacts is hydrogen/deuterium exchange detected by mass spectrometry. In general terms, the hydrogen/deuterium exchange method involves deuterium-labeling the protein of interest, followed by binding the antibody to the deuterium-labeled protein. Next, the protein/antibody complex is transferred to water and exchangeable protons within amino acids that are protected by the antibody complex undergo deuterium-to-hydrogen back-exchange at a slower rate than exchangeable protons within amino acids that are not part of the interface. As a result, amino acids that form part of the protein/antibody interface may retain deuterium and therefore exhibit relatively higher mass compared to amino acids not included in the interface. After dissociation of the antibody, the target protein is subjected to protease cleavage and mass spectrometry analysis, thereby revealing the deuterium-labeled residues that correspond to the specific amino acids with which the antibody interacts. See, e.g., Ehring (1999) Analytical Biochemistry 267: 252-259; Engen and Smith (2001) Anal. Chem. 73: 256A-265A.

The term “epitope” refers to a site on an antigen to which B and/or T cells respond. B-cell epitopes can be formed both from contiguous amino acids or noncontiguous amino acids juxtaposed by tertiary folding of a protein. Epitopes formed from contiguous amino acids are typically retained on exposure to denaturing solvents, whereas epitopes formed by tertiary folding are typically lost on treatment with denaturing solvents. An epitope typically includes at least 3, and more usually, at least 5 or 8-10 amino acids in a unique spatial conformation.

Modification-Assisted Profiling (MAP), also known as Antigen Structure-based Antibody Profiling (ASAP) is a method that categorizes large numbers of monoclonal antibodies (mAbs) directed against the same antigen according to the similarities of the binding profile of each antibody to chemically or enzymatically modified antigen surfaces (see US 2004/0101920, herein specifically incorporated by reference in its entirety). Each category may reflect a unique epitope either distinctly different from or partially overlapping with epitope represented by another category. This technology allows rapid filtering of genetically identical antibodies, such that characterization can be focused on genetically distinct antibodies. When applied to hybridoma screening, MAP may facilitate identification of rare hybridoma clones that produce mAbs having the desired characteristics. MAP may be used to sort the antibodies of the invention into groups of antibodies binding different epitopes.

In certain embodiments, the ZIKV antibodies or antigen-binding fragments thereof bind an epitope within any one or more of the regions exemplified in ZIKV E, either in natural form, or recombinantly produced, or to a fragment thereof.

In one embodiment, escape mutants were generated using the H4H25703N and the H4H25619P antibodies. The results of these studies demonstrated that the serine at position 302 of SEQ ID NO:376 plays a role in H4H25703N antibody binding to the E protein, since a change from a serine to a phenylalanine resulted in loss of binding of the antibody to the mutated E protein and also resulted in loss of virus neutralization capability of the H4H25703N antibody. Likewise, the results with the escape mutants generated using the H4H25619P antibody demonstrated that the threonine at position 311 of SEQ ID NO: 376 and the lysine at position 369 of SEQ ID NO: 376 play a role in binding of H4H25619P to the E protein, since a change from a threonine to an isoleucine at position 311 of SEQ ID NO: 376 and a change from a lysine to a glutamic acid at position 369 resulted in loss of binding of the antibody to the mutated E protein and also resulted in loss of virus neutralization capability of the H4H25619P antibody.

The present invention includes anti-ZIKV E antibodies that bind to the same epitope, or a portion of the epitope. Likewise, the present invention also includes anti-ZIKV E antibodies that compete for binding to ZIKV E or a fragment thereof with any of the specific exemplary antibodies described herein. For example, the present invention includes anti-ZIKV E antibodies that cross-compete for binding to ZIKV with one or more antibodies obtained from those antibodies described in Tables 1 and 2.

One can easily determine whether an antibody binds to the same epitope as, or competes for binding with, a reference anti-ZIKV E antibody by using routine methods known in the art. For example, to determine if a test antibody binds to the same epitope as a reference anti-ZIKV E antibody of the invention, the reference antibody is allowed to bind to a ZIKV E or peptide under saturating conditions. Next, the ability of a test antibody to bind to the ZIKV E is assessed. If the test antibody is able to bind to ZIKV E following saturation binding with the reference anti-ZIKV E antibody, it can be concluded that the test antibody binds to a different epitope than the reference anti-ZIKV antibody. On the other hand, if the test antibody is not able to bind to the ZIKV E following saturation binding with the reference anti-ZIKV E antibody, then the test antibody may bind to the same epitope as the epitope bound by the reference anti-ZIKV E antibody of the invention.

To determine if an antibody competes for binding with a reference anti-ZIKV E antibody, the above-described binding methodology is performed in two orientations: In a first orientation, the reference antibody is allowed to bind to a ZIKV E under saturating conditions followed by assessment of binding of the test antibody to the ZIKV E. In a second orientation, the test antibody is allowed to bind to an ZIKV E under saturating conditions followed by assessment of binding of the reference antibody to the ZIKV E. If, in both orientations, only the first (saturating) antibody is capable of binding to the ZIKV E, then it is concluded that the test antibody and the reference antibody compete for binding to ZIKV E. As will be appreciated by a person of ordinary skill in the art, an antibody that competes for binding with a reference antibody may not necessarily bind to the identical epitope as the reference antibody, but may sterically block binding of the reference antibody by binding an overlapping or adjacent epitope.

Two antibodies bind to the same or overlapping epitope if each competitively inhibits (blocks) binding of the other to the antigen. That is, a 1-, 5-, 10-, 20- or 100-fold excess of one antibody inhibits binding of the other by at least 50% but preferably 75%, 90% or even 99% as measured in a competitive binding assay (see, e.g., Junghans et al., Cancer Res. 1990 50:1495-1502). Alternatively, two antibodies have the same epitope if essentially all amino acid mutations in the antigen that reduce or eliminate binding of one antibody reduce or eliminate binding of the other. Two antibodies have overlapping epitopes if some amino acid mutations that reduce or eliminate binding of one antibody reduce or eliminate binding of the other.

Additional routine experimentation (e.g., peptide mutation and binding analyses) can then be carried out to confirm whether the observed lack of binding of the test antibody is in fact due to binding to the same epitope as the reference antibody or if steric blocking (or another phenomenon) is responsible for the lack of observed binding. Experiments of this sort can be performed using ELISA, RIA, surface plasmon resonance, flow cytometry or any other quantitative or qualitative antibody-binding assay available in the art.

Immunoconjugates

The invention encompasses a human anti-ZIKV E monoclonal antibody conjugated to a therapeutic moiety (“immunoconjugate”), such as an anti-viral drug to treat ZIKV infection. As used herein, the term “immunoconjugate” refers to an antibody, which is chemically or biologically linked to a radioactive agent, a cytokine, an interferon, a target or reporter moiety, an enzyme, a peptide or protein or a therapeutic agent. The antibody may be linked to the radioactive agent, cytokine, interferon, target or reporter moiety, enzyme, peptide or therapeutic agent at any location along the molecule so long as it is able to bind its target. Examples of immunoconjugates include antibody drug conjugates and antibody-toxin fusion proteins. In one embodiment, the agent may be a second different antibody to ZIKV, or ZIKV E. In certain embodiments, the antibody may be conjugated to an agent specific for a virally infected cell. The type of therapeutic moiety that may be conjugated to the anti-ZIKV antibody and will take into account the condition to be treated and the desired therapeutic effect to be achieved. Examples of suitable agents for forming immunoconjugates are known in the art; see for example, WO 05/103081.

Multi-specific Antibodies

The antibodies of the present invention may be mono-specific, bi-specific, or multi-specific. Multi-specific antibodies may be specific for different epitopes of one target polypeptide or may contain antigen-binding domains specific for more than one target polypeptide. See, e.g., Tutt et al., 1991, J. Immunol. 147:60-69; Kufer et al., 2004, Trends Biotechnol. 22:238-244.

Any of the multi-specific antigen-binding molecules of the invention, or variants thereof, may be constructed using standard molecular biological techniques (e.g., recombinant DNA and protein expression technology), as will be known to a person of ordinary skill in the art.

In some embodiments, ZIKV-specific antibodies are generated in a bi-specific format (a “bi-specific”) in which variable regions binding to distinct domains of ZIKV are linked together to confer dual-domain specificity within a single binding molecule. Appropriately designed bi-specifics may enhance overall ZIKV-protein inhibitory efficacy through increasing both specificity and binding avidity. Variable regions with specificity for individual domains, (e.g., segments of the N-terminal domain), or that can bind to different regions within one domain, are paired on a structural scaffold that allows each region to bind simultaneously to the separate epitopes, or to different regions within one domain. In one example for a bi-specific, heavy chain variable regions (V_(H)) from a binder with specificity for one domain are recombined with light chain variable regions (V_(L)) from a series of binders with specificity for a second domain to identify non-cognate V_(L) partners that can be paired with an original V_(H) without disrupting the original specificity for that V_(H). In this way, a single V_(L) segment (e.g., V_(L)1) can be combined with two different V_(H) domains (e.g., V_(H)1 and V_(H)2) to generate a bi-specific comprised of two binding “arms” (V_(H)1-V_(L)1 and V_(H)2-V_(L)1). Use of a single V_(L) segment reduces the complexity of the system and thereby simplifies and increases efficiency in cloning, expression, and purification processes used to generate the bi-specific (See, for example, U.S. Ser. No. 13/022,759 and US2010/0331527).

Alternatively, antibodies that bind more than one domain and a second target, such as, but not limited to, for example, a second different anti-ZIKV antibody, may be prepared in a bi-specific format using techniques described herein, or other techniques known to those skilled in the art. Antibody variable regions binding to distinct regions may be linked together with variable regions that bind to relevant sites on, for example, ZIKV, to confer dual-antigen specificity within a single binding molecule. Appropriately designed bi-specifics of this nature serve a dual function. Variable regions with specificity for the extracellular domain are combined with a variable region with specificity for outside the extracellular domain and are paired on a structural scaffold that allows each variable region to bind to the separate antigens.

An exemplary bi-specific antibody format that can be used in the context of the present invention involves the use of a first immunoglobulin (Ig) C_(H)3 domain and a second Ig C_(H)3 domain, wherein the first and second Ig C_(H)3 domains differ from one another by at least one amino acid, and wherein at least one amino acid difference reduces binding of the bi-specific antibody to Protein A as compared to a bi-specific antibody lacking the amino acid difference. In one embodiment, the first Ig C_(H)3 domain binds Protein A and the second Ig C_(H)3 domain contains a mutation that reduces or abolishes Protein A binding such as an H95R modification (by IMGT exon numbering; H435R by EU numbering). The second C_(H)3 may further comprise a Y96F modification (by IMGT; Y436F by EU). Further modifications that may be found within the second C_(H)3 include: D16E, L18M, N44S, K52N, V57M, and V821 (by IMGT; D356E, L358M, N384S, K392N, V397M, and V4221 by EU) in the case of IgG1 antibodies; N44S, K52N, and V821 (IMGT; N384S, K392N, and V4221 by EU) in the case of IgG2 antibodies; and Q15R, N44S, K52N, V57M, R69K, E79Q, and V821 (by IMGT; Q355R, N384S, K392N, V397M, R409K, E419Q, and V4221 by EU) in the case of IgG4 antibodies. Variations on the bi-specific antibody format described above are contemplated within the scope of the present invention.

Other exemplary bispecific formats that can be used in the context of the present invention include, without limitation, e.g., scFv-based or diabody bispecific formats, IgG-scFv fusions, dual variable domain (DVD)-Ig, Quadroma, knobs-into-holes, common light chain (e.g., common light chain with knobs-into-holes, etc.), CrossMab, CrossFab, (SEED) body, leucine zipper, Duobody, IgG1/IgG2, dual acting Fab (DAF)-IgG, and Mab² bispecific formats (see, e.g., Klein et al. 2012, mAbs 4:6, 1-11, and references cited therein, for a review of the foregoing formats). Bispecific antibodies can also be constructed using peptide/nucleic acid conjugation, e.g., wherein unnatural amino acids with orthogonal chemical reactivity are used to generate site-specific antibody-oligonucleotide conjugates which then self-assemble into multimeric complexes with defined composition, valency and geometry. (See, e.g., Kazane et al., J. Am. Chem. Soc. [Epub: Dec. 4, 2012]).

Therapeutic Administration and Formulations

The invention provides therapeutic compositions comprising the anti-ZIKV E antibodies or antigen-binding fragments thereof of the present invention. Therapeutic compositions in accordance with the invention will be administered with suitable carriers, excipients, and other agents that are incorporated into formulations to provide improved transfer, delivery, tolerance, and the like. A multitude of appropriate formulations can be found in the formulary known to all pharmaceutical chemists: Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, Pa. These formulations include, for example, powders, pastes, ointments, jellies, waxes, oils, lipids, lipid (cationic or anionic) containing vesicles (such as LIPOFECTIN™), DNA conjugates, anhydrous absorption pastes, oil-in-water and water-in-oil emulsions, emulsions carbowax (polyethylene glycols of various molecular weights), semi-solid gels, and semi-solid mixtures containing carbowax. See also Powell et al. “Compendium of excipients for parenteral formulations” PDA (1998) J Pharm Sci Technol 52:238-311.

The dose of antibody may vary depending upon the age and the size of a subject to be administered, target disease, conditions, route of administration, and the like. When an antibody of the present invention is used for treating a disease or disorder in an adult patient, or for preventing such a disease, it is advantageous to administer the antibody of the present invention normally at a single dose of about 0.1 to about 60 mg/kg body weight, more preferably about 5 to about 60, about 10 to about 50, or about 20 to about 50 mg/kg body weight. Depending on the severity of the condition, the frequency and the duration of the treatment can be adjusted. In certain embodiments, the antibody or antigen-binding fragment thereof of the invention can be administered as an initial dose of at least about 0.1 mg to about 800 mg, about 1 to about 500 mg, about 5 to about 300 mg, or about 10 to about 200 mg, to about 100 mg, or to about 50 mg. In certain embodiments, the initial dose may be followed by administration of a second or a plurality of subsequent doses of the antibody or antigen-binding fragment thereof in an amount that can be approximately the same or less than that of the initial dose, wherein the subsequent doses are separated by at least 1 day to 3 days; at least one week, at least 2 weeks; at least 3 weeks; at least 4 weeks; at least 5 weeks; at least 6 weeks; at least 7 weeks; at least 8 weeks; at least 9 weeks; at least 10 weeks; at least 12 weeks; or at least 14 weeks.

Various delivery systems are known and can be used to administer the pharmaceutical composition of the invention, e.g., encapsulation in liposomes, microparticles, microcapsules, recombinant cells capable of expressing the mutant viruses, receptor mediated endocytosis (see, e.g., Wu et al. (1987) J. Biol. Chem. 262:4429-4432). Methods of introduction include, but are not limited to, intradermal, transdermal, intramuscular, intraperitoneal, intravenous, subcutaneous, intranasal, epidural and oral routes. The composition may be administered by any convenient route, for example by infusion or bolus injection, by absorption through epithelial or mucocutaneous linings (e.g., oral mucosa, rectal and intestinal mucosa, etc.) and may be administered together with other biologically active agents. Administration can be systemic or local. The pharmaceutical composition can be also delivered in a vesicle, in particular a liposome (see, for example, Langer (1990) Science 249:1527-1533).

The use of nanoparticles to deliver the antibodies of the present invention is also contemplated herein. Antibody-conjugated nanoparticles may be used both for therapeutic and diagnostic applications. Antibody-conjugated nanoparticles and methods of preparation and use are described in detail by Arruebo, M., et al. 2009 (“Antibody-conjugated nanoparticles for biomedical applications” in J. Nanomat. Volume 2009, Article ID 439389, 24 pages, doi: 10.1155/2009/439389), incorporated herein by reference. Nanoparticles may be developed and conjugated to antibodies contained in pharmaceutical compositions to target virally infected cells. Nanoparticles for drug delivery have also been described in, for example, U.S. Pat. No. 8,257,740, or U.S. Pat. No. 8,246,995, each incorporated herein in its entirety.

In certain situations, the pharmaceutical composition can be delivered in a controlled release system. In one embodiment, a pump may be used. In another embodiment, polymeric materials can be used. In yet another embodiment, a controlled release system can be placed in proximity of the composition's target, thus requiring only a fraction of the systemic dose.

The injectable preparations may include dosage forms for intravenous, subcutaneous, intracutaneous, intracranial, intraperitoneal and intramuscular injections, drip infusions, etc. These injectable preparations may be prepared by methods publicly known. For example, the injectable preparations may be prepared, e.g., by dissolving, suspending or emulsifying the antibody or its salt described above in a sterile aqueous medium or an oily medium conventionally used for injections. As the aqueous medium for injections, there are, for example, physiological saline, an isotonic solution containing glucose and other auxiliary agents, etc., which may be used in combination with an appropriate solubilizing agent such as an alcohol (e.g., ethanol), a polyalcohol (e.g., propylene glycol, polyethylene glycol), a nonionic surfactant [e.g., polysorbate 80, HCO-50 (polyoxyethylene (50 mol) adduct of hydrogenated castor oil)], etc. As the oily medium, there are employed, e.g., sesame oil, soybean oil, etc., which may be used in combination with a solubilizing agent such as benzyl benzoate, benzyl alcohol, etc. The injection thus prepared is preferably filled in an appropriate ampoule.

A pharmaceutical composition of the present invention can be delivered subcutaneously or intravenously with a standard needle and syringe. In addition, with respect to subcutaneous delivery, a pen delivery device readily has applications in delivering a pharmaceutical composition of the present invention. Such a pen delivery device can be reusable or disposable. A reusable pen delivery device generally utilizes a replaceable cartridge that contains a pharmaceutical composition. Once all of the pharmaceutical composition within the cartridge has been administered and the cartridge is empty, the empty cartridge can readily be discarded and replaced with a new cartridge that contains the pharmaceutical composition. The pen delivery device can then be reused. In a disposable pen delivery device, there is no replaceable cartridge. Rather, the disposable pen delivery device comes prefilled with the pharmaceutical composition held in a reservoir within the device. Once the reservoir is emptied of the pharmaceutical composition, the entire device is discarded.

Numerous reusable pen and autoinjector delivery devices have applications in the subcutaneous delivery of a pharmaceutical composition of the present invention. Examples include, but certainly are not limited to AUTOPEN™ (Owen Mumford, Inc., Woodstock, UK), DISETRONIC™ pen (Disetronic Medical Systems, Burghdorf, Switzerland), HUMALOG MIX 75/25™ pen, HUMALOG™ pen, HUMALIN 70/30™ pen (Eli Lilly and Co., Indianapolis, Ind.), NOVOPEN™ I, II and III (Novo Nordisk, Copenhagen, Denmark), NOVOPEN JUNIOR™ (Novo Nordisk, Copenhagen, Denmark), BD™ pen (Becton Dickinson, Franklin Lakes, N.J.), OPTIPEN™, OPTIPEN PRO™, OPTIPEN STARLET™, and OPTICLIK™ (Sanofi-Aventis, Frankfurt, Germany), to name only a few. Examples of disposable pen delivery devices having applications in subcutaneous delivery of a pharmaceutical composition of the present invention include, but certainly are not limited to the SOLOSTAR™ pen (Sanofi-Aventis), the FLEXPEN™ (Novo Nordisk), and the KWIKPEN™ (Eli Lilly), the SURECLICK™ Autoinjector (Amgen, Thousand Oaks, Calif.), the PENLET™ (Haselmeier, Stuttgart, Germany), the EPIPEN (Dey, L. P.) and the HUMIRA™ Pen (Abbott Labs, Abbott Park, Ill.), to name only a few.

Advantageously, the pharmaceutical compositions for oral or parenteral use described above are prepared into dosage forms in a unit dose suited to fit a dose of the active ingredients. Such dosage forms in a unit dose include, for example, tablets, pills, capsules, injections (ampoules), suppositories, etc. The amount of the antibody contained is generally about 5 to about 500 mg per dosage form in a unit dose; especially in the form of injection, it is preferred that the antibody is contained in about 5 to about 100 mg and in about 10 to about 250 mg for the other dosage forms.

Prophylactic or Therapeutic Uses of the Antibodies

The antibodies of the present invention are useful for the treatment, and/or prevention of a disease or disorder or condition associated with ZIKV infection and/or for ameliorating at least one symptom associated with such disease, disorder or condition.

In some embodiments, the antibodies of the invention are useful in decreasing viral titers or reducing viral load in the host. In one embodiment, an antibody or antigen-binding fragment thereof the invention may be administered at a therapeutic dose to a patient with ZIKV infection.

One or more antibodies of the present invention may be administered to relieve or prevent or decrease the severity of one or more of the symptoms or conditions of the disease or disorder. The antibodies may be used to ameliorate or reduce the severity of at least one symptom of ZIKV infection including, but not limited to fever, headache, arthralgia, myalgia, and maculopapular rash.

It is also contemplated herein to use one or more antibodies of the present invention prophylactically to subjects at risk for developing a ZIKV infection such as an immunocompromised individual, a person who has been bitten by a mosquito believed to harbor the ZIKV, a pregnant woman who has been exposed to ZIKV, a woman who lives in, or is visiting a country known to have a ZIKV outbreak and who is considering conceiving a child, an individual visiting, or living in an area known to harbor mosquitoes suspected of carrying the ZIKV, individuals who have visited or are planning to visit an area or country known to have or suspected to have an outbreak of ZIKV.

In a further embodiment of the invention the present antibodies are used for the preparation of a pharmaceutical composition for treating patients suffering from a ZIKV infection, or exposed to ZIKV via a bite by a mosquito harboring the virus. In another embodiment of the invention, the present antibodies are used as adjunct therapy with any other agent or any other therapy known to those skilled in the art useful for treating or ameliorating a ZIKV infection.

Combination Therapies

Combination therapies may include an anti-ZIKV E antibody of the invention and any additional therapeutic agent that may be advantageously combined with an antibody of the invention, or with a biologically active fragment of an antibody of the invention. The antibodies of the present invention may be combined synergistically with one or more drugs or agents used to treat ZIKV infection.

For example, exemplary agents for treating a viral infection may include, e.g., anti-viral drug, an anti-inflammatory drug (such as corticosteroids, and non-steroidal anti-inflammatory drugs, such as anti-TNF), a different antibody to ZIKV, a vaccine for ZIKV, an interferon, an immunomodulator, or any other palliative therapy to treat a ZIKV infection.

In some embodiments, the antibodies of the invention may be combined with a second therapeutic agent to reduce the viral load in a patient with a ZIKV infection, or to ameliorate one or more symptoms of the infection and/or spread to fetus or male reproductive organs.

In certain embodiments, the second therapeutic agent is another different antibody, or antibody cocktail specific for ZIKV E, wherein the different antibody or antibodies within the cocktail may or may not bind to the same epitope, or an overlapping epitope, as an antibody of the present invention. In certain embodiments, the second therapeutic agent is an antibody to a different ZIKV protein. The second antibody may be specific for one or more different ZIKV proteins from different strains of the virus. It is contemplated herein to use a combination (“cocktail”) of the antibodies of the invention with neutralization or inhibitory activity against ZIKV. In some embodiments, non-competing antibodies may be combined and administered to a subject in need thereof, to reduce the ability of ZIKV to escape due to mutation. In some embodiments, the antibodies comprising the combination bind to distinct non-overlapping epitopes on the E. The antibodies comprising the combination may block the virus attachment to the cell, and/or may inhibit fusion of the virus with the cell membrane, and in so doing may block ZIKV entry into the host cells. The antibodies may interact with the E from a strain of ZIKV selected from MR766 (Uganda 1947), PRVABC59 (Puerto Rico 2015) and FLR (Colombia 2015) strains, and when used alone, or in combination with any one or more of the agents noted above, may neutralize any one or more of the ZIKV strains noted, or variants thereof.

It is also contemplated herein to use a combination of anti-ZIKV E antibodies of the present invention, wherein the combination comprises one or more antibodies that do not cross-compete. In certain embodiments, the combination includes a cocktail comprising a mixture of at least two, or at least three antibodies of the invention. The antibodies within the cocktail may differ in their ability to neutralize virus or virus infected cells, or in their ability to block attachment of the virus to the cell, or block fusion of the virus to the cell membrane, or in their ability to bind ZIKV E.

As used herein, the term “in combination with” means that additional therapeutically active component(s) may be administered prior to, concurrent with, or after the administration of at least one anti-ZIKV E antibody of the invention, or a cocktail comprising two or more of the antibodies the present invention. The term “in combination with” also includes sequential or concomitant administration of an anti-ZIKV E antibody and a second therapeutic agent.

The additional therapeutically active component(s) may be administered to a subject prior to administration of an anti-ZIKV E antibody of the present invention. For example, a first component may be deemed to be administered “prior to” a second component if the first component is administered 1 week before, 72 hours before, 60 hours before, 48 hours before, 36 hours before, 24 hours before, 12 hours before, 6 hours before, 5 hours before, 4 hours before, 3 hours before, 2 hours before, 1 hour before, 30 minutes before, 15 minutes before, 10 minutes before, 5 minutes before, or less than 1 minute before administration of the second component. In other embodiments, the additional therapeutically active component(s) may be administered to a subject after administration of an anti-ZIKV E antibody of the present invention. For example, a first component may be deemed to be administered “after” a second component if the first component is administered 1 minute after, 5 minutes after, 10 minutes after, 15 minutes after, 30 minutes after, 1 hour after, 2 hours after, 3 hours after, 4 hours after, 5 hours after, 6 hours after, 12 hours after, 24 hours after, 36 hours after, 48 hours after, 60 hours after, 72 hours after administration of the second component. In yet other embodiments, the additional therapeutically active component(s) may be administered to a subject concurrent with administration of an anti-ZIKV E antibody of the present invention. “Concurrent” administration, for purposes of the present invention, includes, e.g., administration of an anti-ZIKV E antibody and an additional therapeutically active component to a subject in a single dosage form, or in separate dosage forms administered to the subject within about 30 minutes or less of each other. If administered in separate dosage forms, each dosage form may be administered via the same route (e.g., both the anti-ZIKV E antibody and the additional therapeutically active component may be administered intravenously, etc.); alternatively, each dosage form may be administered via a different route (e.g., the anti-ZIKV E antibody may be administered intravenously, and the additional therapeutically active component may be administered orally). In any event, administering the components in a single dosage from, in separate dosage forms by the same route, or in separate dosage forms by different routes are all considered “concurrent administration,” for purposes of the present disclosure. For purposes of the present disclosure, administration of an anti-ZIKV E antibody “prior to”, “concurrent with,” or “after” (as those terms are defined herein above) administration of an additional therapeutically active component is considered administration of an anti-ZIKV E antibody “in combination with” an additional therapeutically active component.

The present invention includes pharmaceutical compositions in which an anti-ZIKV E antibody of the present invention is co-formulated with one or more of the additional therapeutically active component(s) as described elsewhere herein.

Administration Regimens

According to certain embodiments, a single dose of an anti-ZIKV E antibody of the invention (or a pharmaceutical composition comprising one or more antibodies of the invention, or a combination of one or more anti-ZIKV E antibodies and any of the additional therapeutically active agents mentioned herein) may be administered to a subject in need thereof. According to certain embodiments of the present invention, multiple doses of an anti-ZIKV E antibody (or a pharmaceutical composition comprising a combination of anti-ZIKV E antibodies or one or more antibodies of the invention and any of the additional therapeutically active agents mentioned herein) may be administered to a subject over a defined time course. The methods according to this aspect of the invention comprise sequentially administering to a subject multiple doses of one or more anti-ZIKV E antibodies of the invention. As used herein, “sequentially administering” means that each dose of anti-ZIKV E antibody is administered to the subject at a different point in time, e.g., on different days separated by a predetermined interval (e.g., hours, days, weeks or months). The present invention includes methods which comprise sequentially administering to the patient a single initial dose of an anti-ZIKV E antibody, followed by one or more secondary doses of the anti-ZIKV E antibody, and optionally followed by one or more tertiary doses of the anti-ZIKV E antibody.

The terms “initial dose,” “secondary doses,” and “tertiary doses,” refer to the temporal sequence of administration of the anti-ZIKV E antibody of the invention. Thus, the “initial dose” is the dose which is administered at the beginning of the treatment regimen (also referred to as the “baseline dose”); the “secondary doses” are the doses which are administered after the initial dose; and the “tertiary doses” are the doses which are administered after the secondary doses. The initial, secondary, and tertiary doses may all contain the same amount of anti-ZIKV E antibody, but generally may differ from one another in terms of frequency of administration. In certain embodiments, however, the amount of anti-ZIKV E antibody contained in the initial, secondary and/or tertiary doses varies from one another (e.g., adjusted up or down as appropriate) during the course of treatment. In certain embodiments, two or more (e.g., 2, 3, 4, or 5) doses are administered at the beginning of the treatment regimen as “loading doses” followed by subsequent doses that are administered on a less frequent basis (e.g., “maintenance doses”).

In certain exemplary embodiments of the present invention, each secondary and/or tertiary dose is administered 1 to 48 hours (e.g., 1, 1½, 2, 2½, 3, 3½, 4, 4½, 5, 5½, 6, 6½, 7, 7½, 8, 8½, 9, 9½, 10, 10½, 11, 11½, 12, 12½, 13, 13½, 14, 14½, 15, 15½, 16, 16½, 17, 17½, 18, 18½, 19, 19½, 20, 20½, 21, 21½, 22, 22½, 23, 23½, 24, 24½, 25, 25½, 26, 26½, or more) after the immediately preceding dose. The phrase “the immediately preceding dose,” as used herein, means, in a sequence of multiple administrations, the dose of anti-ZIKV E antibody, which is administered to a patient prior to the administration of the very next dose in the sequence with no intervening doses.

The methods according to this aspect of the invention may comprise administering to a patient any number of secondary and/or tertiary doses of an anti-ZIKV E antibody. For example, in certain embodiments, only a single secondary dose is administered to the patient. In other embodiments, two or more (e.g., 2, 3, 4, 5, 6, 7, 8, or more) secondary doses are administered to the patient. Likewise, in certain embodiments, only a single tertiary dose is administered to the patient. In other embodiments, two or more (e.g., 2, 3, 4, 5, 6, 7, 8, or more) tertiary doses are administered to the patient.

In certain embodiments of the invention, the frequency at which the secondary and/or tertiary doses are administered to a patient can vary over the course of the treatment regimen. The frequency of administration may also be adjusted during the course of treatment by a physician depending on the needs of the individual patient following clinical examination.

Diagnostic Uses of the Antibodies

The anti-ZIKV E antibodies of the present invention may be used to detect and/or measure ZIKV in a sample, e.g., for diagnostic purposes. Some embodiments contemplate the use of one or more antibodies of the present invention in assays to detect a disease or disorder such as viral infection. Exemplary diagnostic assays for ZIKV may comprise, e.g., contacting a sample, obtained from a patient, with an anti-ZIKV E antibody of the invention, wherein the anti-ZIKV E antibody is labeled with a detectable label or reporter molecule or used as a capture ligand to selectively isolate ZIKV from patient samples. Alternatively, an unlabeled anti-ZIKV E antibody can be used in diagnostic applications in combination with a secondary antibody which is itself detectably labeled. The detectable label or reporter molecule can be a radioisotope, such as ³H, ¹⁴C, ³²P, ³⁵S, or ¹²⁵I; a fluorescent or chemiluminescent moiety such as fluorescein isothiocyanate, or rhodamine; or an enzyme such as alkaline phosphatase, β-galactosidase, horseradish peroxidase, or luciferase. Specific exemplary assays that can be used to detect or measure ZIKV in a sample include enzyme-linked immunosorbent assay (ELISA), radioimmunoassay (RIA), and fluorescence-activated cell sorting (FACS).

Samples that can be used in ZIKV diagnostic assays according to the present invention include any tissue or fluid sample obtainable from a patient, which contains detectable quantities of either ZIKV, or fragments thereof, under normal or pathological conditions. Generally, levels of ZIKV in a particular sample obtained from a healthy patient (e.g., a patient not afflicted with a disease associated with ZIKV will be measured to initially establish a baseline, or standard, level of ZIKV. This baseline level of ZIKV can then be compared against the levels of ZIKV measured in samples obtained from individuals suspected of having a ZIKV-associated condition, or symptoms associated with such condition.

The antibodies specific for ZIKV may contain no additional labels or moieties, or they may contain an N-terminal or C-terminal label or moiety. In one embodiment, the label or moiety is biotin. In a binding assay, the location of a label (if any) may determine the orientation of the peptide relative to the surface upon which the peptide is bound. For example, if a surface is coated with avidin, a peptide containing an N-terminal biotin will be oriented such that the C-terminal portion of the peptide will be distal to the surface.

EXAMPLES

The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the methods and compositions of the invention, and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to ensure accuracy with respect to numbers used (e.g., amounts, temperature, etc.) but some experimental errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, molecular weight is average molecular weight, temperature is in degrees Centigrade, room temperature is about 25° C., and pressure is at or near atmospheric.

Example 1: Generation of Human Antibodies to ZIKV

Human antibodies to ZIKV were generated in a mouse comprising DNA encoding human immunoglobulin heavy and kappa light chain variable regions. In one embodiment, the human antibodies to ZIKV were generated in a VELOCIMMUNE® mouse. In one embodiment, VelocImmune® (VI) mice were immunized with DNA encoding the ZIKV prM/E (See also GenBank accession number ALU33341.1 and SEQ ID NO: 353). Antibodies were generated following an accelerated regimen comprising 2 immunizations separated by 2 weeks. The antibody immune response was monitored by a ZIKV E-specific immunoassay. For example, sera were assayed for specific antibody titers to virus-like particles (VLPs) produced from cells expressing ZIKV prM/E. Antibody-producing clones were isolated using both B-cell Sorting Technology (BST) and hybridoma methods. For example, when a desired immune response was achieved, splenocytes were harvested and fused with mouse myeloma cells to preserve their viability and form hybridoma cell lines. The hybridoma cell lines were screened and selected to identify cell lines that produce ZIKV E-specific antibodies. Using this technique, and the various immunogens described above, several chimeric antibodies (i.e., antibodies possessing human variable domains and mouse constant domains) were obtained. Exemplary antibodies generated in this manner were designated as H2aM25703N, H2aM25704N, H2aM25708N, H2aM25709N, H2aM25710N, and H2aM25711N.

Anti-ZIKV antibodies were also isolated directly from antigen-positive mouse B cells without fusion to myeloma cells, as described in U.S. Pat. No. 7,582,298, herein specifically incorporated by reference in its entirety. Using this method, several fully human anti-ZIKV E antibodies (i.e., antibodies possessing human variable domains and human constant domains) were obtained; exemplary antibodies generated in this manner were designated as H4H25566P, H4H25587P, H4H25591P, H4H25592P, H4H25598P, H4H25602P, H4H25617P, H4H25619P, H4H25622P, H4H25626P, H4H25630P, H4H25633P, H4H25634P, H4H25637P, H4H25640P, H4H25641P, H4H25703N, H4H25704N, H4H25708N, H4H25709N, H4H25710N, H4H25711N.

The biological properties of the exemplary antibodies generated in accordance with the methods of this Example are described in detail in the Examples set forth below.

Example 2: Heavy and Light Chain Variable Region Amino Acid and Nucleotide Sequences

Table 1 sets forth the amino acid sequence identifiers of the heavy and light chain variable regions and CDRs of selected anti-ZIKV antibodies of the invention. The corresponding nucleic acid sequence identifiers are set forth in Table 2.

TABLE 1 Amino Acid Sequence Identifiers Antibody SEQ ID NOs: Designation HCVR HCDR1 HCDR2 HCDR3 LCVR LCDR1 LCDR2 LCDR3 H4H25566P 2 4 6 8 10 12 14 16 H4H25587P 18 20 22 24 26 28 30 32 H4H25591P 34 36 38 40 42 44 46 48 H4H25592P 50 52 54 56 58 60 62 64 H4H25598P 66 68 70 72 74 76 78 80 H4H25602P 82 84 86 88 90 92 94 96 H4H25617P 98 100 102 104 106 108 110 112 H4H25619P 114 116 118 120 122 124 126 128 H4H25622P 130 132 134 136 138 140 142 144 H4H25626P 146 148 150 152 154 156 158 160 H4H25630P 162 164 166 168 170 172 174 176 H4H25633P 178 180 182 184 186 188 190 192 H4H25634P 194 196 198 200 202 204 206 208 H4H25637P 210 212 214 216 218 220 222 224 H4H25640P 226 228 230 232 234 236 238 240 H4H25641P 242 244 246 248 250 252 254 256 H4H25703N 258 260 262 264 266 268 270 272 H4H25704N 274 276 278 280 282 284 286 288 H4H25708N 290 292 294 296 298 300 302 304 H4H25709N 306 308 310 312 314 316 318 320 H4H25710N 322 324 326 328 330 332 334 336 H4H25711N 338 340 342 344 346 348 350 352 H2aM25703N 258 260 262 264 266 268 270 272 H2aM25704N 274 276 278 280 282 284 286 288 H2aM25708N 290 292 294 296 298 300 302 304 H2aM25709N 306 308 310 312 314 316 318 320 H2aM25710N 322 324 326 328 330 332 334 336 H2aM25711N 338 340 342 344 346 348 350 352

TABLE 2 Nucleic Acid Sequence Identifiers Antibody SEQ ID NOs: Designation HCVR HCDR1 HCDR2 HCDR3 LCVR LCDR1 LCDR2 LCDR3 H4H25566P 1 3 5 7 9 11 13 15 H4H25587P 17 19 21 23 25 27 29 31 H4H25591P 33 35 37 39 41 43 45 47 H4H25592P 49 51 53 55 57 59 61 63 H4H25598P 65 67 69 71 73 75 77 79 H4H25602P 81 83 85 87 89 91 93 95 H4H25617P 97 99 101 103 105 107 109 111 H4H25619P 113 115 117 119 121 123 125 127 H4H25622P 129 131 133 135 137 139 141 143 H4H25626P 145 147 149 151 153 155 157 159 H4H25630P 161 163 165 167 169 171 173 175 H4H25633P 177 179 181 183 185 187 189 191 H4H25634P 193 195 197 199 201 203 205 207 H4H25637P 209 211 213 215 217 219 221 223 H4H25640P 225 227 229 231 233 235 237 239 H4H25641P 241 243 245 247 249 251 253 255 H4H25703N 257 259 261 263 265 267 269 271 H4H25704N 273 275 277 279 281 283 285 287 H4H25708N 289 291 293 295 297 299 301 303 H4H25709N 305 307 309 311 313 315 317 319 H4H25710N 321 323 325 327 329 331 333 335 H4H25711N 337 339 341 343 345 347 349 351 H2aM25703N 257 259 261 263 265 267 269 271 H2aM25704N 273 275 277 279 281 283 285 287 H2aM25708N 289 291 293 295 297 299 301 303 H2aM25709N 305 307 309 311 313 315 317 319 H2aM25710N 321 323 325 327 329 331 333 335 H2aM25711N 337 339 341 343 345 347 349 351

Antibodies are typically referred to herein according to the following nomenclature: Fc prefix (e.g. “H1H,” “H4H,” “H2aM” etc.), followed by a numerical identifier (e.g. “25566,” “25587”, “25710” etc., as shown in Table 1 or 2), followed by a “P,” “P2,” “N”, N2, or “B” suffix. The H1H and H4H prefixes on the antibody designations used herein indicate the particular Fc region isotype of the antibody. Thus, according to this nomenclature, an antibody may be referred to herein as, e.g., “H4H25566P”, “H2aM25703N”, etc. For example, an “H4H” antibody has a human IgG4 Fc and an “H2aM” antibody has a mouse IgG2a Fc (all variable regions are fully human as denoted by the first ‘H’ in the antibody designation). As will be appreciated by a person of ordinary skill in the art, an antibody having a particular Fc isotype can be converted to an antibody with a different Fc isotype (e.g., an antibody with a mouse IgG1 Fc can be converted to an antibody with a human IgG4, etc.), but in any event, the variable domains (including the CDRs)—which are indicated by the numerical identifiers shown in Table 1 or 2—will remain the same, and the binding properties to antigen are expected to be identical or substantially similar regardless of the nature of the Fc domain.

Example 3: Binding Assay to Assess Binding of Monoclonal Antibodies to Zika Pre-membrane-envelope Intermediate (prM/E) Polyprotein

To investigate the ability of a panel of anti-ZIKV monoclonal antibodies to bind ZIKV E, an in vitro binding assay utilizing ZIKV viral-like particles (VLPs) prepared from prM/E-expressing cells in an electrochemiluminescence based detection platform (MSD) was developed.

VLPs were generated from HEK293T/17 cells transiently expressing the ZIKV prM/E polyprotein (Accession number ALU33341.1 (also shown as SEQ ID NO: 353), amino acid residues 123-795 of ZIKV polyprotein). VLPs prepared from cells expressing the Vesicular stomatitis virus (VSV) glycoprotein (G) were also generated as a negative binding control. Included in the experiment are negative controls for human IgG4 and mouse IgG2a antibodies as irrelevant negative controls for the IgG detection antibodies.

Experiments were carried out according to the following procedure. VLPs from the two sources described above were diluted in PBS, seeded into the 96-well carbon electrode plates (MULTI-ARRAY high bind plate, MSD) and incubated overnight at 4° C. to allow the VLPs to adhere. Nonspecific binding sites were blocked by 2% BSA (w/v) in PBS for 1 hour at room temperature. To the plate-bound particles, anti-ZIKV and control antibodies in serial dilutions ranging from 1.7 pM to 100 nM in 1×PBS+0.5% BSA buffer, and buffer only, were added in duplicate, and the plates were incubated for 1 hour at room temperature. The plates were then washed with 1×PBS to remove the unbound antibodies using an AquaMax2000 plate washer (MDS Analytical Technologies). The plate-bound antibodies were detected with a SULFO-TAG™-conjugated anti-human IgG antibody (Meso Scale Development) or a SULFO-TAG™-conjugated anti-mouse IgG antibody (Jackson Immunoresearch) for 1 hour at room temperature. After washes, the plates were developed with the Read Buffer (MSD) according to manufacturer's recommended procedure and the luminescent signals were recorded with a SECTOR Imager 600 (MSD) instrument. The direct binding signals (in RLU) were analyzed as a function of the antibody concentration and the data were fitted with a sigmoidal (four-parameter logistic) dose-response model using GraphPad Prism™ software. The EC₅₀ values, defined as the concentration of antibody at which 50% of the maximal binding signal is detected, was determined for ZIKV prM/E VLPs to indicate potency of each antibody. In addition, ratios of the binding signals of the antibodies at 11.1 nM on ZIKV prM/E VLPs to the irrelevant VSV G VLPs were calculated. The antibodies with the binding ratio less than 2 were marked as NB in Table 3. NB refers to no specific binding observed under assay conditions.

Results Summary and Conclusions:

The ability of the anti-ZIKV monoclonal antibodies to bind specifically ZIKV VLPs prepared form prM/E expressing cells compared with binding to irrelevant VSV G-containing VLPs was assessed using an immunobinding assay. Antibody dose dependent binding to the immobilized VLPs on 96-well High Bind plates (MSD), with antibody concentrations up to 100 nM, were detected using SULFO-TAG™-conjugated anti-human IgG or anti-mouse IgG antibody, and the binding signals in electrochemiluminescence were recorded on a Sector Imager 600 (MSD). RLU values were determined for the antibody binding to VLPs. For the ZIKV prM/E VLPs EC₅₀ values were calculated as a measure of potency. For antibodies with irrelevant background affecting ZIKV binding profiles, higher concentrations were excluded from calculation of EC₅₀ values and values are italicized in the table. Comparison of the binding signals of the antibodies at 11.1 nM to ZIKV prM/E and irrelevant expressing VLPs was used to evaluate the binding specificity to the ZIKV protein. Specific binding is defined as antibodies having a ratio of 2-fold or higher binding to ZIKV prM/E expressing VLPs compared to irrelevant VLPs at that concentration.

The binding results are summarized in Table 3. EC₅₀ values for binding to the ZIKV prM/E VLPs are reported and range from 87 pM to 133 nM for the test antibodies. For antibodies, H4H25640P and H4H25704N, binding values at higher concentrations were excluded from calculation of EC₅₀ values to compensate for high background on the irrelevant VSV G VLPs. Ratios of binding on ZIKV prM/E VLPs vs binding to the VSV G VLPs at 11.1 nM concentration are also reported. All test antibodies evaluated bound specifically to ZIKV prM/E VLPs. Negative isotype control antibodies did not bind specifically, as expected (Data not shown).

TABLE 3 Ratio of RLU Zika Binding to Zika prM/E VLP/VSV G VLP at Ab PID VLPs EC50 (M) 11.1 nM H4H25566P 8.20E−10 6 H4H25587P 1.45E−10 14 H4H25591P 1.02E−10 3 H4H25592P 2.13E−10 7 H4H25598P 4.26E−10 7 H4H25602P 1.56E−09 5 H4H25617P 7.55E−10 8 H4H25619P 1.92E−09 7 H4H25622P 2.44E−09 7 H4H25626P 1.59E−09 10 H4H25630P 2.17E−10 9 H4H25633P 4.00E−10 9 H4H25634P 3.23E−10 11 H4H25637P 3.22E−10 9 H4H25640P 1.02E−10 2 H4H25641P 2.87E−09 6 H4H25703N 8.46E−11 8 H4H25708N 1.33E−07 4 H4H25704N 1.80E−10 4 H4H25710N 5.42E−10 13 H2aM25710N 2.44E−10 107 H2aM25709N 3.62E−10 244 H2aM25711N 4.68E−10 263 Italicized values have high antibody concentrations excluded from EC₅₀ calculations.

Example 4: Antibody Binding to ZIKV prM80E as Determined by Surface Plasmon Resonance

A. pH Dependent Dissociation Rate Constants

Dissociation rate constants for zika (prM80E)-mmH binding to purified anti-ZIKV mAbs were determined using a real-time surface plasmon resonance biosensor using a Biacore 4000 instrument (Catalog nr. 28-9643-21). The Biacore CM5 sensor surface was derivatized by amine coupling with a polyclonal goat anti-human Fc antibody (Jackson Laboratories, #BR-109005-098) to capture anti-ZIKV antibodies expressed with human constant regions. Biacore pH chase studies were performed in a buffer composed of 0.01M Na₂HPO₄/NaH₂PO₄, 0.15M NaCl, 0.05% v/v Surfactant P20 (PBS-P running buffer) at pH 7.4, 6.0, 5.5 and 5.0. ZIKV (prM80E) with a C-terminal myc-myc-his tag (SEQ ID NO: 354), hereby referred to as ZIKV-mmH, was prepared in PBS-P running buffer (at a concentration of 30 nM) and was injected over the anti-ZIKV mAb captured surface at a flow rate of 30 μL/minute. Association of ZIKV-mmH to the captured monoclonal antibody was monitored for 3 minutes at in PBS-P running buffer at pH7.4 and the dissociation of ZIKV-mmH in PBS-P running buffer at pH7.4, pH6.0, pH5.5 or pH5.0 was monitored for 10 minutes. All of the pH chase experiments were performed at 37° C. Kinetic dissociation (k_(d)) rate constants were determined by fitting the real-time sensorgrams to a 1:1 binding model using Scrubber 2.0c curve fitting software. Dissociative half-lives (t½) were calculated from the kinetic rate constants as: t½(min)=ln 2/(60×k _(d))

Binding kinetic parameters for ZIKV-mmH binding to purified anti-ZIKV mAbs at 37° C. are shown in Tables 4A and 4B.

TABLE 4A 37° C. Binding Kinetics Results at pH 7.4 and 6.0 pH 7.4 pH 6.0 30 nM 30 nM Zika Zika t½ mAb prM80E mAb prM80E pH 7.4/ REGN Capture Bound kd t½ Capture Bound kd t½ t½ Nr/Ab PID # (RU) (RU) (1/s) (min) (RU) (RU) (1/s) (min) pH 6.0 H4H25566P 113.3 14.1 5.42E−02 0.21 111.5 6.9 2.99E−01 0.04 5.5 H4H25587P 65.4 20.1 1.80E−02 0.64 62.2 22.1 1.51E−02 0.77 0.8 H4H25591P 159.9 62.7 6.30E−03 1.83 161.8 62.3 1.36E−02 0.85 2.2 H4H25592P 126.7 57.9 1.74E−03 6.63 123 59.6 5.03E−03 2.3 2.9 H4H25598P 65.5 29.3 3.97E−04 29.13 59.8 28.8 1.29E−02 0.9 32.4 H4H25602P 95.4 31.5 3.56E−04 32.46 92.5 32.2 1.22E−02 0.95 34.1 H4H25617P 28.3 13.6 6.02E−03 1.92 19.2 14.1 4.94E−03 2.34 0.8 H4H25619P 79.2 15.8 1.93E−03 6 73.8 18.4 1.02E−03 11.29 0.5 H4H25622P 66.8 18 3.18E−03 3.63 56.8 16.5 2.34E−03 4.93 0.7 H4H25626P 8 1.3 IC IC 4.1 1.5 IC IC IC H4H25630P −11.6 −0.5 IC IC −21.6 −1.5 IC IC IC H4H25633P 8.6 0.6 IC IC 4.7 1.5 IC IC IC H4H25634P 26.3 15 1.19E−02 0.97 15.4 15 5.85E−03 1.98 0.5 H4H25637P 119.9 37.6 1.18E−02 0.98 116.4 38.5 3.92E−03 2.95 0.3 H4H25640P 104.7 55.6 1.72E−03 6.72 102.2 58.5 3.23E−03 3.58 1.9 H4H25641P 85.9 23.4 1.91E−02 0.61 79.7 25.1 1.59E−02 0.73 0.8 H4H25703N 153.4 74.6 2.11E−03 5.47 158.7 77.3 2.83E−03 4.08 1.3 H4H25708N 69.9 22.5 2.60E−03 4.45 67.8 25.4 1.44E−03 8.02 0.6 H4H25704N 78.1 46.6 1.21E−03 9.56 74.9 49.7 1.31E−03 8.85 1.1 H4H25710N 82.7 21.3 5.41E−03 2.14 81.1 21.1 1.30E−01 0.09 24 IC = inconclusive NB no binding

TABLE 4B 37° C. Binding Kinetics Results at pH 5.5 and 5.0 pH 5.5 pH 5.0 30 nM 30 nM t½ Zika t½ Zika pH 7.4/ REGN mAb prM80E pH 7.4/ mAb prM80E t½ Nr/Ab Capture Bound kd t½ t½ Capture Bound kd t½ pH PID # (RU) (RU) (1/s) (min) pH 5.5 (RU) (RU) (1/s) (min) 5.0 H4H25566P 96.8 6.4 3.92E−01 0.03 7.2 101.5 6.1 3.68E−01 0.03 6.8 H4H25587P 63.7 27.2 1.74E−02 0.66 1 46.2 23.6 1.77E−02 0.7 1 H4H25591P 145 62.1 1.84E−02 0.63 2.9 151.6 57.7 1.48E−02 0.8 2.4 H4H25592P 124.6 66.7 7.36E−03 1.57 4.2 111.7 61.5 6.58E−03 1.8 3.8 H4H25598P 44.9 26.9 7.41E−02 0.16 187 54 22.4 1.14E−01 0.1 288 H4H25602P 94.3 37 4.76E−02 0.24 134 81.8 30.4 9.70E−02 0.1 272 H4H25617P −0.2 15.2 4.65E−03 2.48 0.8 10.4 13.4 4.64E−03 2.5 0.8 H4H25619P 71.9 24.6 9.53E−04 12.12 0.5 59.1 21.2 5.48E−04 21.1 0.3 H4H25622P 42.8 19.3 1.78E−03 6.49 0.6 49.8 16.9 7.04E−04 16.4 0.2 H4H25626P −1.1 5 IC IC IC −6.5 1 IC IC IC H4H25630P −35.2 −2.6 IC IC IC −22.7 −3.9 IC IC IC H4H25633P 0.5 1.7 IC IC IC −8.3 −2.9 IC IC IC H4H25634P −4 17.3 6.11E−03 1.89 0.5 6.4 14 5.53E−03 2.1 0.5 H4H25637P 118.2 42.6 4.14E−03 2.79 0.4 105.1 38.9 2.28E−03 5.1 0.2 H4H25640P 86.1 60 4.02E−03 2.87 2.3 92.4 55.3 3.37E−03 3.4 2 H4H25641P 79.5 29.9 2.04E−02 0.57 1.1 65.4 24.8 1.33E−02 0.9 0.7 H4H25703N 145.5 79.9 3.26E−03 3.54 1.5 148.6 73 2.80E−03 4.1 1.3 H4H25708N 68.2 31.1 1.57E−03 7.37 0.6 51.4 25.9 1.29E−03 8.9 0.5 H4H25704N 59.2 52.4 1.07E−03 10.77 0.9 65.8 49.4 9.59E−04 12 0.8 H4H25710N 81 20 1.81E−01 0.06 33.4 65.9 11.5 3.39E−01 0.03 62.6 IC = inconclusive NB no binding Results and Summary

The effect of pH on the dissociation (kd and t½) of ZIKV.mmH from anti-ZIKV antibodies were studied at pH 7.4, 6.0, 5.5 and 5.0, at 37° C. The anti-ZIKV antibodies H4H25710N, H4H25602P and H4H25598P of the invention showed the highest pH dependent changes in dissociation. Anti-ZIKV antibody H4H25566P showed moderate pH dependent changes in dissociation while the rest of the ZIKV-antibodies did not show significant pH dependent changes in dissociation.

B. Binding Affinity and Kinetics at 25° C. and 37° C.

Equilibrium dissociation constants (K_(D) values) for ZIKV (prM80E)-mmH protein binding to purified anti-ZIKV monoclonal antibodies were determined using a real-time surface plasmon resonance biosensor assay on a Biacore 4000 instrument. The Biacore sensor surface was derivatized by amine coupling with a polyclonal goat anti-human Fc antibody (Jackson Laboratories, #BR-109005-098) to capture anti-ZIKV antibodies expressed with human constant regions. Biacore binding studies were performed in HBS-P running buffer (0.01M HEPES pH 7.4, 0.15M NaCl, 0.05% v/v Surfactant P20). ZIKV (prM80E) protein with a C-terminal myc-myc-hexahistidine tag (mmH) was prepared in-house and here by referred to as ZIKV-mmH (See SEQ ID NO: 354). Different concentrations (3-fold dilutions) of ZIKV-mmH (ranging from 30 nM to 0.37 nM), prepared in HBS-P running buffer were injected over the anti-ZIKV antibody captured surface at a flow rate of 30 μL/min. Association of ZIKV-mmH to each of the captured monoclonal antibodies was monitored for 3 minutes and dissociation was monitored for 8 minutes in HBS-P running buffer. All binding kinetics experiments were performed at either 25° C. or 37° C. Kinetic association (k_(a)) and dissociation (k_(d)) rate constants were determined by fitting the real-time sensorgrams to a 1:1 binding model using Scrubber 2.0c curve fitting software. Binding dissociation equilibrium constants (K_(D)) and dissociative half-lives (t½) were calculated from the kinetic rate constants as:

${{K_{D}(M)} = {\frac{kd}{ka}/k_{a}}},{{{and}\mspace{14mu}{t^{1/2}\left( \min \right)}} = \frac{\ln(2)}{60*{kd}}}$

Binding kinetic parameters for ZIKV-mmH binding to anti-ZIKV antibodies at 25° C. and 37° C. are shown in Tables 5 and 6.

TABLE 5 Binding kinetics parameters of anti-ZIKV monoclonal antibodies binding to ZIKV (prM80E)-mmH at 25° C. Amount of 30 nM antibody ZIKV-mmH captured bound k_(a) k_(d) K_(D) t½ Antibody (RU) (RU) (1/Ms) (1/s) (M) (min) H4H25566P 218.4 ± 0.9 49.5 5.90E+05 1.63E−02 2.77E−08 0.7 H4H25587P 151.2 ± 2.1 68.8 8.22E+05 4.22E−03 5.13E−09 2.7 H4H25591P 291.6 ± 5.1 103.6 6.49E+05 3.18E−03 4.90E−09 3.6 H4H25592P 263.4 ± 3.2 123.3 1.35E+06 6.76E−04 5.02E−10 17.1 H4H25598P 206.8 ± 1.7 64.7 2.89E+05 4.49E−05 1.56E−10 257.3 H4H25602P 218.4 ± 4.8 68.8 2.86E+05 1.95E−05 7.00E−11 592.0 H4H25617P 144.6 ± 2.3 41.6 2.50E+05 1.97E−03 7.90E−09 5.9 H4H25619P 202.5 ± 3.2 39.3 1.64E+05 5.16E−04 3.14E−09 22.4 H4H25622P 186.0 ± 2.7 32.5 2.51E+05 1.33E−03 5.31E−09 8.7 H4H25626P 354.7 ± 6.3 55.1 1.47E+05 9.05E−04 6.17E−09 12.8 H4H25630P 252.6 ± 2.8 140.7 1.67E+06 3.50E−04 2.10E−10 33.0 H4H25633P 258.4 ± 3.1 76.1 4.11E+05 8.02E−04 1.95E−09 14.4 H4H25634P 142.2 ± 2.0 54.7 6.47E+05 5.44E−03 8.41E−09 2.1 H4H25637P 331.7 ± 3.3 126.8 6.17E+05 3.91E−03 6.33E−09 3.0 H4H25640P 291.7 ± 7.7 129.3 1.21E+06 7.22E−04 5.97E−10 16.0 H4H25641P 189.5 ± 3.1 57.8 1.05E+06 9.22E−03 8.75E−09 1.3 H4H25703N 390.8 ± 6.6 169.1 5.66E+05 3.07E−04 5.42E−10 37.6 H4H25708N 176.3 ± 1.6 56.0 4.17E+05 5.04E−04 1.21E−09 22.9 H4H25704N 222.0 ± 3.6 110.0 1.33E+06 3.59E−04 2.70E−10 32.2 H4H25710N 186.4 ± 1.1 48.4 2.99E+05 2.09E−03 6.99E−09 5.5

TABLE 6 Binding kinetics parameters of anti-ZIKV monoclonal antibodies binding to ZIKV (prM80E)-mmH at 37° C. Amount of antibody 30 nM ZIKV- captured mmH bound k_(a) k_(d) K_(D) t½ Antibody (RU) (RU) (1/Ms) (1/s) (M) (min) H4H25566P 178.0 ± 9.6 20.8 6.87E+05 3.60E−02 5.25E−08 0.3 H4H25587P 100.1 ± 7.9 51.3 1.10E+06 1.45E−02 1.32E−08 0.8 H4H25591P  271.8 ± 11.8 112.0 8.16E+05 6.82E−03 8.37E−09 1.7 H4H25592P  216.4 ± 10.9 120.0 1.61E+06 1.65E−03 1.02E−09 7.0 H4H25598P 168.9 ± 9.9 75.3 4.06E+05 2.84E−04 7.00E−10 40.7 H4H25602P  193.0 ± 10.6 83.7 3.81E+05 2.84E−04 7.45E−10 40.6 H4H25617P 112.1 ± 7.1 34.3 4.52E+05 7.29E−03 1.61E−08 1.6 H4H25619P 166.3 ± 9.6 44.3 1.93E+05 1.08E−03 5.59E−09 10.7 H4H25622P 120.3 ± 3.5 30.1 2.95E+05 2.67E−03 9.07E−09 4.3 H4H25626P 237.2 ± 6.5 61.5 3.03E+05 1.87E−03 6.18E−09 6.2 H4H25630P 164.6 ± 4.6 102.5 1.98E+06 2.29E−03 1.16E−09 5.1 H4H25633P 152.1 ± 4.4 53.4 6.78E+05 5.01E−03 7.39E−09 2.3 H4H25634P  87.3 ± 2.5 36.8 8.66E+05 1.01E−02 1.17E−08 1.1 H4H25637P 240.5 ± 5.5 93.7 9.92E+05 9.89E−03 9.97E−09 1.2 H4H25640P 221.8 ± 7.9 109.6 1.47E+06 1.86E−03 1.27E−09 6.2 H4H25641P 142.2 ± 4.0 45.6 1.59E+06 1.88E−02 1.19E−08 0.6 H4H25703N 267.5 ± 6.8 134.8 7.38E+05 1.77E−03 2.39E−09 6.5 H4H25708N  93.9 ± 2.3 47.7 7.81E+05 2.32E−03 2.97E−09 5.0 H4H25704N 142.5 ± 2.6 83.3 1.93E+06 1.20E−03 6.21E−10 9.6 H4H25710N 119.2 ± 2.1 36.2 5.19E+05 6.40E−03 1.24E−08 1.8 Results and Summary

At 25° C., all 20 anti-zika antibodies of the invention bound to ZIKV-.mmH with K_(D) values ranging from 70 pM to 27.7 nM (Table 5). At 37° C., the anti-ZIKV antibodies of the invention bound to ZIKV-mmH with K_(D) values ranging from 621 pM to 52.5 nM (Table 6). As expected, the negative isotype controlshowed no binding (data not shown).

Example 5: Neutralization of ZIKV with Antibodies Specific for ZIKV E

Vero cells (African Green Monkey kidney—ATCC® CCL81) were seeded 1 day prior to infection with ZIKV, at 10,000 cells per well in Corning black 96-well cell culture plates with a clear bottom in MEM-alpha complete medium containing 10% heat inactivated FBS and penicillin/streptomycin/L-glutamine.

The strains of ZIKV used for infection of Vero cells were MR766 (Isolated from a sentinel rhesus monkey in Uganda, 1947. Accession # AY632535), FLR (Isolated from a human in Colombia in December 2015. Accession # KU820897) and PRVABC59 (Isolated from a human in Puerto Rico in December 2015. Accession # KU501215).

On the day of neutralization/infection, test antibodies were diluted to 2×concentration in DMEM containing 2% heat inactivated FBS penicillin/streptomycin/L-glutamine and mixed 1:1 with ZIKV for 30 minutes at 37° C.

Media was removed from the plated Vero cells, which were then incubated with 1:1 mixture of antibody and virus for 1 hour at 37° C., with gentle agitation of the assay plates every 15 minutes. Antibody treated virus inoculum was removed and the cells were overlaid with 100 uL of DMEM containing 1% heat inactivated FBS, penicillin/streptomycin/L-glutamine and 1% methyl cellulose and incubated overnight (12-16 hours) at 37° C. at 5% CO2.

The following day, the overlay media was aspirated off the cells, which were washed twice with PBS, then fixed with an ice cold 1:1 mixture of acetone and methanol for 30 minutes at 4° C. Fixed cells were washed twice with PBS, then permeabilized with PBS containing 0.1% Triton-X and 5% FBS for 15 minutes at room temperature. Cells were washed once with PBS alone, followed by incubation with PBS containing 5% FBS for 30 minutes at room temperature to block non-specific binding. Cells were then incubated with a polyclonal antibody (Zika Mouse Immune Ascitic Fluid-obtained from UTMB) at a 1:10,000 dilution in PBS containing 5% FBS and 0.1% Tween-20 for 1 hour at room temperature. Cells were washed 6 times with 300 uL PBS using the Molecular Devices AquaMax 4000 plate washer, then incubated with secondary antibody (Life Technologies Alexa-488 conjugated goat-anti-mouse IgG) for 1 hour at room temperature in the dark. Cells were washed 6 times on the plate washer and 100 uL PBS was added prior to analysis. Analysis was completed using the SpectraMax with Mini Max plate reader by imaging each well and using settings to count distinct fluorescent foci.

Neutralization % was calculated as follows:

${\%\mspace{14mu}{Neutralization}} = \frac{\begin{matrix} {{\#\mspace{14mu}{of}\mspace{14mu}{infected}\mspace{14mu}{cells}\mspace{14mu}{at}\mspace{14mu}{each}\mspace{14mu}{mAb}\mspace{14mu}{concentration}} -} \\ {{assay}\mspace{14mu}{b{ackground}}} \end{matrix}}{{\#\mspace{14mu}{of}\mspace{14mu}{infected}\mspace{14mu}{cells}\mspace{14mu}{in}\mspace{14mu}{virus}\mspace{14mu}{only}\mspace{14mu}{control}} - {{assay}\mspace{14mu}{background}}}$

The results, expressed as % neutralization, were analyzed using nonlinear regression (4-parameter logistics) with Prism 5 software (GraphPad Software, Inc.) to obtain IC₅₀ values. Results are shown in Tables 7 and 8 below.

Results Summary and Conclusions:

The data shown below in Table 7 and 8 show that 18 out of the 20 anti-ZIKV virus antibodies of the present invention, using the experimental design described herein, potently neutralize infectivity of ZIKV strains MR766, PRVABC59 (Puerto Rico 2015) and FLP (Colombia 2015) with an IC₅₀ ranging from about 10⁻¹¹ M to about 10⁻⁹M. As expected, the negative isotype control showed no neutralization (data not shown).

TABLE 7 PRVABC59 MR766 Puerto Rico FLR Uganda 1947 2015 Colombia 2015 Ab PID IC50 (M) IC50 (M) IC50 (M) H4H25587P 1.50E−10 3.21E−10 9.55E−10 H4H25598P 5.45E−11 3.98E−10 5.53E−10 H4H25602P 5.31E−11 5.01E−10 6.30E−10 H4H25630P 1.47E−10 5.39E−10 2.83E−10 H4H25633P 1.02E−10 6.52E−10 4.40E−10 H4H25710N 4.71E−11 1.24E−09 1.06E−09 H4H25591P 3.43E−11 2.54E−10 3.30E−10 H4H25592P 4.26E−11 2.18E−10 5.53E−10 H4H25634P 1.39E−10 1.45E−10 2.07E−10 H4H25637P 6.71E−11 2.39E−10 1.34E−10 H4H25640P 2.79E−11 1.66E−10 9.90E−11 H4H25641P 3.71E−11 3.56E−10 2.12E−10 H4H25703N 4.45E−11 2.51E−10 6.19E−11 H4H25704N 4.60E−11 2.78E−10 7.58E−11 H4H25617P 1.66E−10 5.43E−10 5.52E−10 H4H25566P Partial Partial 1.55E−09 neutralization neutralization H4H25619P 1.71E−10 1.14E−09 1.26E−09 H4H25622P 1.88E−10 1.28E−09 1.58E−09 H4H25626P 1.59E−10 1.17E−09 1.09E−09 H4H25708N 3.49E−10 non neutralizing non neutralizing

TABLE 8 MR766 Ab PID IC50 (M) H2aM25703N ~2.095e−011   H2aM25708N 1.07E−10 H2aM25710N 1.70E−11 H2aM25704N 2.21E−10

Example 6: Octet Cross Competition Assay

To assess whether two antibodies compete with one another for binding to their epitopes on ZIKV (prM80E)-mmH hereby referred to as ZIKV.mmH (SEQ ID NO: 354), binding competition between anti-ZIKV monoclonal antibodies was determined using a real time, label-free bio-layer interferometry assay on an Octet RED384 biosensor (Pall ForteBio Corp.). Cross competition experiments were performed at 25° C. in 0.01 M HEPES pH7.4, 0.15M NaCl, 0.05% v/v Surfactant Tween-20, 0.1 mg/mL BSA (HBS-P buffer) with the plate shaking at the speed of 1000 rpm. All anti-ZIKV antibody and ZIKV-mmH solutions tested were prepared in Octet HBS-P buffer. To assess whether 2 antibodies were able to compete with one another for binding to their respective epitopes on ZIKV-mmH, approximately ˜0.97-0.112 nm of ZIKV-mmH was first captured on anti-His coated Octet biosensor tips from wells containing 10 μg/mL of ZIKV-mmH for 90 seconds. The ZIKV-mmH captured Octet biosensor tips were saturated by submerging for 5 minutes into wells containing 20 ug/ml of the first anti-ZIKV monoclonal antibody (hereby referred to as mAb-1), followed by submerging in wells containing the second anti-ZIKV monoclonal antibody (hereby referred to as mAb-2). Between steps, the Octet biosensor tips were washed in HBS-P buffer for 30 seconds.

The real-time binding response was monitored during the course of the experiment and the binding response at the end of every step was recorded. The response of ZIKV-mmH binding to mAb-1 and then to the blocking mAb was corrected for background binding, compared and competitive/non-competitive behavior of different anti-ZIKV monoclonal antibodies was determined.

Table 9 explicitly defines the relationships of antibodies competing in both directions, independent of the order of binding. Two anti-ZIKV monoclonal antibodies, H4H25619P and H4H25703N did not cross compete with the remaining antibodies described in this invention.

TABLE 9 Cross-competition of anti-ZIKV antibodies for binding to ZIKV-mmH. mAb-1 mAb-2 H4H25710N H4H25633P H4H25602P H4H25598P H4H25630P H4H25587P H4H25633P H4H25710N H4H25602P H4H25598P H4H25630P H4H25587P H4H25602P H4H25710N H4H25633P H4H25598P H4H25630P H4H25587P H4H25598P H4H25710N H4H25633P H4H25602P H4H25630P H4H25587P H4H25630P H4H25710N H4H25633P H4H25602P H4H25598P H4H25587P H4H25587P H4H25710N H4H25633P H4H25602P H4H25598P H4H25630P H4H25634P H4H25641P H4H25703N H4H25592P H4H25591P H4H25704N H4H25640P H4H25637P H4H25617P H4H25641P H4H25634P H4H25703N H4H25592P H4H25591P H4H25704N H4H25640P H4H25637P H4H25617P H4H25703N H4H25634P H4H25641P H4H25592P H4H25591P H4H25704N H4H25640P H4H25637P H4H25617P H4H25592P H4H25634P H4H25641P H4H25703N H4H25591P H4H25704N H4H25640P H4H25637P H4H25617P H4H25591P H4H25634P H4H25641P H4H25703N H4H25592P H4H25704N H4H25640P H4H25637P H4H25617P H4H25704N H4H25634P H4H25641P H4H25703N H4H25592P H4H25591P H4H25640P H4H25637P H4H25617P H4H25640P H4H25634P H4H25641P H4H25703N H4H25592P H4H25591P H4H25704N H4H25637P H4H25617P H4H25637P H4H25634P H4H25641P H4H25703N H4H25592P H4H25591P H4H25704N H4H25640P H4H25617P H4H25617P H4H25634P H4H25641P H4H25703N H4H25592P H4H25591P H4H25704N H4H25640P H4H25637P H4H25619P H4H25622P H4H25626P H4H25566P H4H25622P H4H25619P H4H25626P H4H25566P H4H25626P H4H25619P H4H25622P H4H25566P H4H25566P H4H25619P H4H25622P H4H25526P

Example 7: Measurement of Antibody Dependent Enhancement (ADE) Using an Immunofluorescence Assay

Experiments were conducted to determine the effect of ZIKV antibodies on Antibody Dependent Enhancement (ADE) using an immunofluorescence assay (described below).

In one experiment, chimeric antibodies that cross-react with all Flaviviruses were made using the heavy chain and light chain sequences found in GenBank accession numbers KJ438784 (kappa light chain) and KJ438785.1 (heavy chain). Three antibodies were made, designated REGN4203 (hIgG1), REGN4204 (hlgG4s) and REGN4206 (hlgG4us). REGN4203 has a heavy chain (HC) shown in SEQ ID NO: 359 and a light chain (LC) shown in SEQ ID NO: 360. REGN4204 has a heavy chain (HC) shown in SEQ ID NO: 361 and a light chain (LC) shown in SEQ ID NO: 362 and REGN4206 has a heavy chain (HC) shown in SEQ ID NO: 363 and a light chain (LC) shown in SEQ ID NO: 364.

In another experiment, two anti-Zika virus antibodies designated H4H25703N (HCVR/LCVR amino acid sequence pairs of SEQ ID NOs: 258/266) and H4H25619P (HCVR/LCVR amino acid sequence pairs of SEQ ID NOs: 114/122) were tested for their effects on ADE using the same immunofluorescence assay. Each of the anti-Zika antibodies, H4H25703N and H4H25619P, was prepared as either an IgG1 having an Fc comprising the amino acid sequence of SEQ ID NO: 356, or as an IgG4 having an Fc comprising the amino acid sequence shown in SEQ ID NO: 357. The full-length amino acid sequence of the heavy chain (HC) of H4H25703N is shown as SEQ ID NO: 367 and the full length amino acid sequence of the light chain (LC) of H4H25703N is shown as SEQ ID NO: 368. The full-length amino acid sequence of the heavy chain (HC) of H4H25619P is shown as SEQ ID NO: 370 and the full-length amino acid sequence of the light chain (LC) of H4H25619P is shown as SEQ ID NO: 371.

Antibodies were diluted to 2× for final concentrations of 50, 10, 2, 0.4, and 0.08 ug/mL in RPMI+10% FBS, 1× Penicillin/Streptomycin/Glutamine. 100 uL of each antibody was then mixed 1:1 with RPMI complete media containing 2500 ffu (fluorescence focus units) virus for 30 minutes at 37° C., 5% CO₂. 80,000 K562 cells in 300 uL RPMI complete media was then added to the antibody/virus mixture and incubated at 37° C., 5% CO₂ for 3 days. At 1 and 2 days post-infection, 100 uL supernatant was removed and frozen to −80° C. At day 3, the remainder of the supernatant was collected and frozen to −80° C.

To detect the viral load of the supernatant, Vero cells were seeded at 10,000 cells/well in black/clear-bottom 96-well cell culture plates in MEM-alpha containing 10% FBS, Penicillin/Streptomycin/Glutamine. Cells were incubated at 37° C., 5% CO₂ overnight. On the day of infection, supernatant samples from above were diluted in RPMI complete media. 50 uL of each dilution was added to Vero cells and incubated for 1 hour at 37° C., 5% CO₂ with gentle agitation of the plates every 15 minutes. Inoculum was removed from the cells and cells were overlaid with 100 uL DMEM+1% FBS, 1×Penicillin/Streptomycin/Glutamine, 1% methyl cellulose and incubated at 37° C., 5% CO₂ overnight.

Infected cells were quantitated by an immunofluorescence assay as previously described in Example 5.

Results

As shown in FIG. 1, REGN4203 demonstrated an increase in ADE as shown by the increase in virus yield when the concentration of antibody increased from 10⁻¹⁰M to 10⁻⁷M. REGN4204 showed a modest increase in virus yield as the concentration of antibody increased from 10⁻¹⁰M to 10⁻⁷M. However, REGN4206 had no effect on ADE as shown by its inability to increase virus yield as the concentration of antibody increased from 10⁻¹⁰M to 10⁻⁷M. In fact, REGN4206 showed no difference as compared to the virus only control.

As shown in FIGS. 6 and 7, unlike their IgG1 versions, the anti-ZIKV antibodies, when prepared as an IgG4 having an Fc comprising the amino acid sequence shown in SEQ ID NO: 357, do not induce ADE activity.

Example 8: Effect of anti-ZIKV antibodies on Protection in ZIKV Infected Mice

A study was done to determine the effect of anti-ZIKV antibodies in a mouse model of ZIKV infection.

Briefly, one day prior to infection, two anti-ZIKV antibodies, designated H4H25703N and H4H25619P, were diluted in PBS for final concentrations of 200, 50, or 12.5 μg per 200 μL dose. One day later, interferon alpha/beta receptor 1 (IFNAR1) KO mice were dosed with the antibodies via subcutaneous injection into the loose dorsal scruff area. On the day of infection, ZIKV, strain FSS13025, was diluted in DMEM media containing 2% heat-inactivated fetal bovine serum with 1× penicillin/streptomycin/glutamine to 10⁵ ffu per 200 μL dose. The mice were dosed with the virus via intraperitoneal injection. The mice were monitored for weight loss throughout the course of the experiment up to 21 days post-infection. Animals whose body weight dropped below an 80% threshold or those experiencing extreme morbidity (shaking, weakness, and non-responsiveness) were euthanized. Those animals, which were euthanized, show date of death as one day post-euthanasia (for example, an animal culled at 6 days post-infection is denoted as surviving until day 7).

Results

The results, as shown in FIGS. 2-5, show that all mice receiving the isotype control antibody lost greater than 20% of their body weight by day 9 after infection and had to be sacrificed according to IACUC guidelines. Mice receiving either the H4H25703 anti-ZIKV antibody (FIG. 2) or the H4H25619P anti-ZIKV antibody (FIG. 3) were able to better control their body weight loss up to 21 days post infection; no mice in the 200 ug and 50 ug groups and 40% of the mice in the 12.5 ug groups displayed a weight loss of more than the 20% threshold. Pre-treatment of mice with H4H25703N (FIG. 4) or H4H25619 (FIG. 5) also improved their survival; 100% of mice treated with 200 ug or 50 ug of either antibody or 60% of mice treated with 12.5 ug of each antibody survived challenge with ZIKV.

Example 9: In Vitro Generation of ZIKV Escape Mutants to Determine the Binding Sites for H4H25703N and H4H25619P

4×10⁵ ffu MR766 ZIKV was combined with increasing concentrations of H4H25703N or H4H25619P (or isotype control antibody) at each antibody's IC50, IC75, IC85, IC99, IC99, and IC99.99 as calculated from the IC50 and hill slope of the neutralization curve analysis when plotted in GraphPad Prism (log(inhibitor) vs. response—variable slope (four parameter)). The calculations were completed as follows where f=the desired fraction (for IC85, f=85) and H=hill slope:

${IC}_{f} = \left( \frac{F}{100 - F} \right)^{1/H}$

Virus and antibody were incubated together for 30 minutes at 37° C. prior to addition onto 2×10⁵ Vero cells* that had been seeded one day prior to infection in a 24-well plate. Cells were incubated at 37° C., 5% CO2 and checked daily for cytopathic effect. Once cytopathic effect was evident in the wells treated with isotype control antibody, the viral supernatant was collected from the H4H25703N and H4H25619P treated wells and cleared of debris by centrifugation. The viral supernatant from the well with the highest concentration of antibody where cytopathic effect was seen was then incubated with fresh antibody and passed onto fresh pre-seeded cells, and again incubated at 37° C., 5% CO2 until cytopathic effect was evident. This cycle was repeated until cytopathic effect was seen at the highest antibody concentration (IC99.99). Viral supernatant was collected from the IC99.99 well and passed to a T25 flask pre-seeded with 6×10⁶ Vero cells. Once cytopathic effect was visible on these cells, the virus was collected, cleared by centrifugation, and used in a neutralization assay to verify its escape, and also to determine whether the virus was still able to be neutralized by the second antibody. The infected cells from this virus expansion were also collected into 1 mL Trizol for RNA isolation and sequence analysis of the virus.

Neutralization Assay**

To confirm whether the escape mutants generated under the pressure of H4H25703N and H4H25619P were resistant to neutralization, a neutralization assay in Vero cells was performed. Briefly, to complete the neutralization, virus was combined with decreasing concentrations of either H4H25703N, H4H25619P, or isotype control antibody at concentrations from 10 ug/mL diluted 3-fold down to 200 pg/mL for an 11-point curve. Virus and antibodies were incubated together at 37° C. for 30 minutes prior to addition onto 10,000 Vero cells pre-seeded in black, clear-bottom 96-well cell culture plates. Cells were incubated with virus/antibody mixture for 1 hour with gentle agitation periodically throughout the incubation. After the incubation, the inoculum was removed and the cells were overlaid with DMEM containing 1% methyl cellulose*** and incubated at 37° C., 5% CO2 overnight. The methyl cellulose overlay was aspirated from the cells, which were then washed twice with PBS and fixed with an ice cold 1:1 mixture of acetone and methanol for 30 minutes at 4 C. Fixed cells were washed twice with PBS, then permeabilized with PBS containing 5% FBS and 0.1% Triton-X for 15 minutes at room temperature. Cells were washed with PBS then incubated with PBS containing 5% FBS to block nonspecific binding for 30 minutes at room temperature. Cells were then incubated with primary antibody (polyclonal immunized mouse ascites fluid) at a 1:10,000 dilution in PBS+5% FBS and 0.1% Tween-20 for 1 hour at room temperature. Cells were washed 6 times with PBS using a Molecular Devices AquaMax 4000 plate washer, then incubated with secondary antibody (Alexa-488 conjugated goat-anti-mouse IgG) at 1 ug/mL in PBS+5% FBS and 0.1% Tween-20 for 1 hour in the dark at room temperature. Cells were washed 6 times on the plate washer and left in 100 uL PBS for analysis on the Spectramax with MiniMax plate reader to count fluorescent foci. Percent neutralization is calculated as follows and was plotted in GraphPad Prism in a nonlinear regression (log(inhibitor) vs. response—variable slope (four parameter)): % Neutralization=(1−((well value-media only control)/(virus only control-media only control)))*100 Once neutralization was confirmed, RNA was isolated from the infected cells from the virus expansion using Trizol (Life Technologies), following the manufacturer's protocol. The resulting RNA was used for cDNA synthesis using the Life Technologies SuperScript III First Strand Synthesis system. This cDNA was used as template in a PCR to amplify the Zika E sequence using the following parameters:

Primers: MR766 PCR Fwd: TGGGTTGTGTACGGAACCTG          (SEQ ID NO: 379)          MR766 PCR Rev: GGCACTGGCAATCTTTGTGG          (SEQ ID NO: 380) 1 uL cDNA 1 uL each primer (100 uM) 4 uL 10% DMSO 33 uL AccuPrime Pfx Supermix Cycling: 95 C for 5 minutes 3 cycles of: 95 C for 15 seconds              54 C for 15 seconds              72 C for  2 minutes 35 cycles of: 95 C for 15 seconds               56 C for 15 seconds               72 C for  2 minutes *Vero cells cultured and seeded in DMEM high glucose media containing 10% heat-inactivated FBS and penicillin/streptomycin/L-glutamine **Neutralization reactions and virus growth were completed in DMEM high glucose media containing 2% heat-inactivated FBS and penicillin/streptomycin/L-glutamine ***Methyl cellulose overlay contains 1X DMEM with 1% heat-inactivated FBS, penicillin/streptomycin/L-glutamine, and 1% methyl cellulose

The resulting PCR product (expected size: 2113 bp) was run on a 1% agarose TBE gel containing 1× Sybr Safe DNA Stain (Life Technologies) at 120V for 1 hour. The amplicon was cut out and purified using the Qiagen QiaQuick Gel Extraction Kit following the manufacturer's instructions. The resulting purified product sequenced using the Sanger method using the following primers:

MR766 seq1: TGATACTGCTGATTGCCCCG (SEQ ID NO: 381) MR766 seq2: AACACAAGGTGAAGCCTAC (SEQ ID NO: 382) MR766 seq3: AAGAGGCAAACCGTCGTCGTTC (SEQ ID NO: 383) MR766 seq4: CCCGTGATTACTGAAAGCAC (SEQ ID NO: 384) MR766 seq5: GTTCAACTCACTGGGTAAGG (SEQ ID NO: 385)

Sequences were analyzed and assembled to compose the full Zika E sequence. Translation of the sequence assembly revealed escape mutations.

Results

Sequence analysis confirmed that the escape mutation for H4H25703N was found at position 302 of the Zika virus E protein (SEQ ID NO: 376; S302E). The escape mutations for H4H25619P were found at amino acid positions 311 and 369 of the Zika virus E protein (SEQ ID NO: 376; T311I and K369E, respectively). The amino acid sequence showing the E protein escape mutation (5302F) for H4H25703N is shown as SEQ ID NO: 377. The amino acid sequence showing the E protein escape mutations (T311I and K369E) for H4H25619P is shown as SEQ ID NO: 378. The data from these studies suggest binding sites for H4H25703N and H4H25619P on ZIKV E protein that may play a major role in viral neutralization. In addition, the results shown in FIGS. 8A and 8B demonstrate that while one antibody may not neutralize ZIKV because of a mutation in the E protein, a second antibody may be capable of neutralizing that virus containing a mutation in the E protein, thus providing support for the use of an antibody cocktail.

Example 10: Effect of Anti-ZIKV Antibody Combinations on Protection in ZIKV Infected Mice

A study was done to determine the effect of anti-ZIKV antibodies, when used alone or in combination in a mouse model of ZIKV infection.

Interferon alpha/beta receptor 1 (IFNAR1) KO mice were received at 6-8 weeks of age and injected subcutaneously with 200 μL PBS containing either a negative isotype control antibody, or anti-ZIKV antibodies for final doses of 200, 50, or 12.5 μg antibody per mouse. When two of the antibodies were combined, each antibody was given at a dose of 100, 25, or 6.25 μg, so that the total dose of both antibodies when combined was 200, 50 or 12.5 μg. One day post-treatment, the mice were infected via intraperitoneal injection with 105 ffu Zika virus strain FSS13025 diluted in DMEM+2% FBS, 1× Penicillin/Streptomycin/Glutamine (PSG). The animals were monitored for up to 3 weeks for weight loss or extreme sickness. Animals were euthanized if they dropped below a weight threshold of 80% of starting weight or exhibited extreme sickness (qualified by tremors or non-responsiveness—animals with hind limb paralysis were monitored for recovery in the experiment).

Results

The results showed that all mice receiving the isotype control antibody lost greater than 20% of their body weight by day 9 after infection and had to be sacrificed according to IACUC guidelines. Pre-treatment of mice with H4H25703N or H4H25619 at doses of 200 ug or 50 ug resulted in 100% survival. 60% of mice treated with 12.5 ug of H4H25703 survived challenge with ZIKV. 75% of mice treated with 12.5 ug of H4H25619 survived challenge with ZIKV. Pretreatment of mice with both antibodies at total doses of 200 ug (100 ug of each antibody) or 50 ug (25 ug of each antibody) resulted in 100% survival. Pretreatment of mice with a total dose of 12.5 ug (6.25 ug of each antibody) also resulted in 100% survival. These results suggest that a lower dose of each antibody can be used in combination to achieve greater efficacy, as compared to that attained when each antibody is used alone. The results are shown in Table 10 below.

TABLE 10 Antibody % Survival Identification Final Dose of Ab used (in ug) Number 200 50 12.5 H4H25703 100% 100% 60% H4H25619 100% 100% 75% H4H25703 + 100% 100% 100% H4H25619 

What is claimed is:
 1. An isolated recombinant monoclonal antibody or antigen-binding fragment thereof that specifically binds to ZIKA virus (ZIKV) and/or a ZIKV envelope glycoprotein (E), wherein the antibody or antigen-binding fragment thereof neutralizes ZIKV in vitro with an IC₅₀ less than or equal to about 10⁻⁹M and wherein the antibody or antigen-binding fragment thereof comprises three complementarity determining regions (CDRs) of a heavy chain variable region (HCVR) comprising the amino acid sequence of SEQ ID NO: 114, and three CDRs of a light chain variable region (LCVR) comprising the amino acid sequence of SEQ ID NO:
 122. 2. The isolated monoclonal antibody or antigen-binding fragment of claim 1, comprising a HCVR comprising the amino acid sequence of SEQ ID NO: 114, and a LCVR comprising the amino acid sequence of SEQ ID NO:
 122. 3. The isolated monoclonal antibody or antigen-binding fragment thereof of claim 1, comprising an HCDR1 amino acid sequence of SEQ ID NO: 116; an HCDR2 amino acid sequence of SEQ ID NO: 118; an HCDR3 amino acid sequence of SEQ ID NO: 120; an LCDR1 amino acid sequence of SEQ ID NO: 124; an LCDR2 amino acid sequence of SEQ ID NO: 126 and an LCDR3 amino acid sequence of SEQ ID NO:
 128. 4. The isolated monoclonal antibody or antigen-binding fragment thereof of claim 1, whereby the antibody further comprises an Fc domain having the amino acid sequence of SEQ ID NO:
 357. 5. The isolated monoclonal antibody or antigen-binding fragment thereof of claim 4, wherein the antibody or antigen-binding fragment thereof does not contribute to Antibody Dependent Enhancement (ADE).
 6. The isolated monoclonal antibody or antigen-binding fragment of claim 1, having one or more of the following characteristics: (a) is a fully human monoclonal antibody; (b) binds to a VLP expressing ZIKV prM/E with an EC₅₀ ranging from about 80 pM to about 150 nM; (c) binds to ZIKV E with a dissociation constant (K_(D)) of less than 10⁻⁷M, as measured in a surface plasmon resonance assay; or (d) may or may not demonstrate a change in dissociative half-life (t½) at pH 5 or pH 6 relative to pH 7.4.
 7. A pharmaceutical composition comprising the isolated monoclonal antibody or antigen-binding fragment thereof according to claim 1, and a pharmaceutically acceptable carrier or diluent.
 8. The pharmaceutical composition of claim 7, further comprising one or more additional isolated monoclonal antibodies or antigen-binding fragments thereof that bind specifically to ZIKV and comprise the three heavy chain complementarity determining regions (HCDR1, HCDR2 and HCDR3) contained within any one of the heavy chain variable region (HCVR) sequences selected from the group consisting of SEQ ID NOs: 2, 18, 34, 50, 66, 82, 98, 130, 146, 162, 178, 194, 210, 226, 242, 258, 274, 290, 306, 322 and 338; and the three light chain complementarity determining regions (LCDR1, LCDR2 and LCDR3) contained within any one of the light chain variable region (LCVR) sequences selected from the group consisting of SEQ ID NOs: 10, 26, 42, 58, 74, 90, 106, 138, 154, 170, 186, 202, 218, 234, 250, 266, 282, 298, 314, 330 and
 346. 9. The pharmaceutical composition of claim 8, wherein the one or more additional isolated monoclonal antibodies that bind specifically to ZIKV comprise an HCVR/LCVR amino acid sequence pair selected from the group consisting of SEQ ID NOs: 2/10, 18/26, 34/42, 50/58, 66/74, 82/90, 98/106, 130/138, 146/154, 162/170, 178/186, 194/202, 210/218, 226/234, 242/250, 258/266, 274/282, 290/298, 306/314, 322/330 and 338/346.
 10. The pharmaceutical composition of claim 9, wherein the one or more additional isolated monoclonal antibodies that bind specifically to ZIKV comprise an HCVR/LCVR amino acid sequence pair selected from the group consisting of SEQ ID NOs: 66/74, and 258/266.
 11. The pharmaceutical composition of claim 7, further comprising an isolated monoclonal antibody that binds specifically to ZIKV and comprises a HCVR comprising the amino acid sequence of SEQ ID NO: 258 and a LCVR comprising the amino acid sequence of SEQ ID NO:
 266. 12. The pharmaceutical composition of claim 7, further comprising an isolated monoclonal antibody that binds specifically to ZIKV and comprises a HCDR1 having the amino acid sequence of SEQ ID NO: 260, a HCDR2 having the amino acid sequence of SEQ ID NO: 262, a HCDR3 having the amino acid sequence of SEQ ID NO: 264, a LCDR1 having the amino acid sequence of SEQ ID NO: 268, a LCDR2 having the amino acid sequence of SEQ ID NO: 270, a LCDR3 having the amino acid sequence of SEQ ID NO:
 272. 13. The pharmaceutical composition of claim 7, wherein the antibody or antigen-binding fragment neutralizes one or more ZIKV strains selected from the group consisting of MR766 (Uganda 1947), PRVABC59 (Puerto Rico 2015) and FLR (Colombia 2015) strains, as measured in an in vitro neutralization assay.
 14. A fully human antibody or antigen-binding fragment thereof that specifically binds to ZIKA virus (ZIKV) and/or a ZIKV envelope glycoprotein (E), and comprises three complementarity determining regions (CDRs) of a heavy chain variable region (HCVR) comprising the amino acid sequence of SEQ ID NO: 114, and three CDRs of a light chain variable region (LCVR) comprising the amino acid sequence of SEQ ID NO:
 122. 15. A fully human antibody or antigen-binding fragment thereof that specifically binds to ZIKA virus (ZIKV) and/or a ZIKV envelope glycoprotein (E), and comprises complementarity determining regions HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 comprising the amino acid sequences of SEQ ID NOs: 116-118-120-124-126-128, respectively.
 16. The fully human antibody or antigen-binding fragment of claim 15, comprising a HCVR comprising the amino acid sequence of SEQ ID NO: 114 and a LCVR comprising the amino acid sequence of SEQ ID NO:
 122. 17. The fully human antibody or antigen-binding fragment of claim 16 that is an antibody.
 18. The fully human antibody of claim 17, comprising an Fc domain comprising the amino acid sequence of SEQ ID NO:
 357. 19. The fully human antibody of claim 17, comprising an Fc domain comprising the amino acid sequence of SEQ ID NO:
 358. 20. A pharmaceutical composition comprising the fully human antibody or antigen-binding fragment thereof of claim
 14. 21. A pharmaceutical composition comprising the fully human antibody or antigen-binding fragment thereof of claim
 15. 22. A pharmaceutical composition comprising the fully human antibody or antigen-binding fragment thereof of claim
 16. 23. A pharmaceutical composition comprising the fully human antibody of claim
 18. 24. A pharmaceutical composition comprising the fully human antibody of claim
 19. 